Citation Nr: 1341452 Decision Date: 12/16/13 Archive Date: 12/31/13 DOCKET NO. 08-08 558 ) DATE ) ) On appeal from the Department of Veterans Affairs (VA) Regional Office (RO) in Providence, Rhode Island THE ISSUES 1. Whether new and material evidence has been received to reopen a claim of entitlement to service connection for esophageal cancer, and if so, whether service connection is warranted. 2. Entitlement to service connection for sleep apnea, to include as secondary to service-connected posttraumatic stress disorder (PTSD). 3. Entitlement to special monthly compensation (SMC) based on loss of use of a creative organ. REPRESENTATION Appellant represented by: Vietnam Veterans of America WITNESS AT HEARING ON APPEAL Appellant ATTORNEY FOR THE BOARD C. L. Wasser, Counsel INTRODUCTION The Veteran served on active duty from February 1965 to October 1968. This case comes to the Board of Veterans' Appeals (Board) on appeal from rating decisions by the RO in Providence, Rhode Island. In a June 2007 rating decision, the RO denied entitlement to service connection for diabetes mellitus and sleep apnea, and denied entitlement to SMC based on loss of use of a creative organ. In an April 2009 rating decision, the RO determined that new and material evidence had not been received to reopen the previously denied claim for service connection for esophageal cancer. The Veteran was notified of this decision by a letter dated in April 2009. The Board finds that during the year following notice of this rating decision, new and material evidence was received from the Veteran and his representative. See 38 C.F.R. § 3.156(b). In an April 2010 rating decision, the RO determined that new and material evidence had been received to reopen the previously denied claim for service connection for esophageal cancer, and then denied the service connection claim on the merits. In a September 2011 decision and remand, the Board granted entitlement to service connection for diabetes mellitus, and remanded the issues of service connection for sleep apnea and entitlement to SMC based on loss of use of a creative organ for additional evidentiary development. The case was subsequently returned to the Board. In January 2013, the Board determined that the Veteran had perfected an appeal of the RO's April 2010 decision which reopened a previously denied claim for service connection for esophageal cancer and then denied service connection for this disability. The Board remanded this issue, as well as the other issues on appeal, for a Board hearing pursuant to the Veteran's request. The case was returned to the Board. In April 2013, a personal hearing was held before the undersigned Veterans Law Judge of the Board at the RO (i.e., a Travel Board hearing). A transcript of this hearing is of record. The RO denied the Veteran's original claim for entitlement to service connection for esophageal cancer in an unappealed October 2007 rating decision. As the claim for service connection for esophageal cancer was previously denied in a prior final RO decision, the Board must determine for purposes of jurisdiction whether there is new and material evidence sufficient to reopen this claim. Jackson v. Principi, 265 F.3d 1366 (Fed. Cir. 2001); Barnett v. Brown, 83 F.3d 1380 (Fed. Cir. 1996). And, as will be discussed below, the Board is reopening this claim. Additional pertinent evidence was received from the Veteran in May and July 2013. The Veteran has waived initial RO review of this evidence and the Board will consider it. 38 C.F.R. § 20.1304. Since the March 2011 statement of the case regarding service connection for esophageal cancer, the RO has associated additional VA treatment records with the Veteran's electronic Virtual VA folder, and issued a supplemental statement of the case in July 2012 with respect to the sleep apnea and SMC claims. As these records are not relevant to the issue of service connection for esophageal cancer, remand for issuance of a supplemental statement of the case is not required. See 38 C.F.R. §§ 19.31, 19.37. The issue of entitlement to SMC based on loss of use of a creative organ is addressed in the REMAND portion of the decision below and is REMANDED to the RO via the Appeals Management Center (AMC), in Washington, DC. FINDINGS OF FACT 1. The RO previously denied the claim for service connection for esophageal cancer in an October 2007 rating decision and appropriately notified the Veteran of the decision and of his procedural and appellate rights, but he did not appeal that decision. 2. Some of the evidence since received is not cumulative or redundant of evidence already of record and considered in the October 2007 decision, and raises a reasonable possibility of substantiating this claim. 3. The Veteran served in the Republic of Vietnam during the Vietnam era; therefore, exposure to an herbicide agent (the dioxin in Agent Orange) is presumed. 4. The Veteran's esophageal cancer developed many years after his military service, and the most probative (meaning competent and credible) medical and other evidence indicates this cancer was unrelated to his service, including his presumed exposure to herbicides during his tour in Vietnam. 5. There is an approximate balance of evidence for and against his claim as to whether he has current sleep apnea that was permanently aggravated by service-connected PTSD, including the medication for treatment of this disorder. CONCLUSIONS OF LAW 1. The October 2007 rating decision that denied the Veteran's claim of entitlement to service connection for esophageal cancer is final and binding based on the evidence then of record. 38 U.S.C.A. § 7105 (West 2002); 38 C.F.R. §§ 3.104(a), 3.160(d), 20.200, 20.1103 (2013). 2. New and material evidence having been received, the claim for service connection for esophageal cancer is reopened. 38 U.S.C.A. § 5108 (West 2002); 38 C.F.R. § 3.156 (2013). 3. The Veteran's esophageal cancer was not incurred in or aggravated by his military service, nor may it be presumed to have been so incurred or aggravated, including as a result of his presumed exposure to herbicides (Agent Orange) in Vietnam. 38 U.S.C.A. §§ 1101, 1110, 1112, 1113, 1116, 5107 (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309 (2013). 4. Resolving all reasonable doubt in his favor, the Veteran's current sleep apnea was aggravated by service-connected PTSD during the pendency of the appeal. 38 U.S.C.A. §§ 1110, 5107 (West 2002); 38 C.F.R. §§ 3.102, 3.303, 3.310 (2013). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Duties to Notify and Assist As provided by the Veterans Claims Assistance Act (VCAA), VA has duties to notify and assist a claimant in substantiating a claim for VA benefits. 38 U.S.C.A. §§ 5100, 5102, 5103, 5103A, 5107, 5126 (West 2002); 38 C.F.R. §§ 3.102, 3.156(a), 3.159 and 3.326(a) (2013). Proper notice from VA must inform the claimant of any information and medical or lay evidence not of record (1) that is necessary to substantiate the claim; (2) that VA will obtain and assist the claimant in obtaining; and (3) that the claimant is expected to provide. See 38 C.F.R. § 3.159(b)(1); see also Quartuccio v. Principi, 16 Vet. App. 183, 187 (2002); Charles v. Principi, 16 Vet. App. 370, 373-74 (2002). These VCAA notice requirements apply to all five elements of a service-connection claim: (1) Veteran status; (2) existence of a disability; (3) a connection between the Veteran's service and the disability; (4) degree of disability; and (5) effective date of the disability. See Dingess/Hartman v. Nicholson, 19 Vet. App. 473 (2006), aff'd sub nom. Hartman v. Nicholson, 483 F.3d 1311 (2007). Further, this notice must include information that a downstream disability rating and an effective date for the award of benefits will be assigned if service connection is granted. Id., at 486. In Kent v. Nicholson, 20 Vet. App. 1 (2006), the United States Court of Appeals for Veterans Claims (Court) held that VA must both notify a claimant of the evidence and information that is necessary to reopen a previously denied claim and of the evidence and information necessary to establish entitlement to the underlying benefit being sought, i.e., service connection. Here, in light of the favorable disposition regarding the issue of entitlement to service connection for sleep apnea, discussion of these duties to notify and assist the Veteran with this claim is unnecessary because the sleep apnea claim is being granted. That is, even were the Board to assume, for the sake of argument, he has not received this required notification and assistance, this ultimately would be inconsequential and, therefore, amount to no more than nonprejudical, i.e., harmless error. 38 C.F.R. § 20.1102. See also Shinseki v. Sanders, 129 S. Ct. 1696 (2009) (clarifying that VCAA notice and assistance errors are not presumptively prejudicial, rather, must be determined on a case-by-case basis and that, as the pleading party attacking the agency's decision, the Veteran, not VA, bears this burden of proof of not only establishing this error but also showing how it is unduly prejudicial, meaning outcome determinative of the claim). With respect to the application to reopen a previously denied claim for service connection for esophageal cancer, and the reopened claim for service connection for this disability, a December 2008 letter was sent to the Veteran regarding this claim, prior to the April 2009 rating decision on appeal. This letter provided notice regarding what information and evidence is needed to substantiate the underlying claim for service connection. Although this letter failed to discuss the requirement to submit new and material evidence to reopen the claim for service connection for esophageal cancer, pursuant to Kent, supra, the Board finds that this failure did not prejudice the Veteran, as both the RO and now the Board have reopened this claim and considered it on the merits. The December 2008 letter advised the Veteran as to what information and evidence must be submitted by him, and the types of evidence that will be obtained by VA, as well as information regarding disability ratings and effective dates. The appellant has neither alleged nor demonstrated any prejudice with regard to the content or timing of the notice provided. Shinseki v. Sanders, 129 S. Ct. 1696 (2009) (burden of showing that an error is harmful or prejudicial falls upon the party attacking the agency determination). VA also fulfilled its duty to assist the Veteran by obtaining all relevant evidence in support of his claims, which is obtainable, and therefore appellate review may proceed without prejudicing him. 38 U.S.C.A. § 5103A (West 2002 & Supp. 2012); 38 C.F.R. § 3.159 (2013); see also Bernard v. Brown, 4 Vet. App. 384 (1993). The Veteran has submitted records and written statements in support of his claims. A review of the claims file shows that VA has obtained the Veteran's service treatment records (STRs), service personnel records, pertinent VA and private treatment records, and arranged for VA compensation examinations. The Board notes that a VA compensation examination has not been conducted with respect to the claim for service connection for esophageal cancer, and finds that a remand for such an examination is not required, as the evidence of record is sufficient to adjudicate this claim. The Veteran has submitted extensive medical and other evidence in support of his claim, and his own lay statements requesting service connection. As will be discussed below, the Board has also considered 38 C.F.R. § 3.309(e), and a report by the National Academy of Sciences (NAS), Veterans and Agent Orange: Update 2010 (Update 2010). See Waters v. Shinseki, 601 F.3d 1274, 1278-79 (Fed. Cir. 2010) (rejecting the theory that medical examinations are to be routinely and virtually automatically provided to all veterans in disability cases involving nexus issues). For these reasons, the Board finds that a VA examination is not warranted. Neither the appellant nor his representative has identified, and the record does not otherwise indicate, any additional existing evidence that is necessary for a fair adjudication of the claims that has not been obtained. The Board further finds that the RO has substantially complied with its September 2011 and January 2013 remand orders. In this regard, the Board directed that the RO should obtain the Veteran's VA medical records, arrange for a VA examination regarding the sleep apnea claim, and schedule a Travel Board hearing, and this was done. Therefore, the Board finds that no further development is necessary in this regard. See D'Aries v. Peake, 22 Vet. App. 97, 105 (2008); Dyment v. West, 13 Vet. App. 141, 146-47 (1999) (remand not required under Stegall v. West, 11 Vet. App. 268 (1998), where the Board's remand instructions were substantially complied with), aff'd, Dyment v. Principi, 287 F.3d 1377 (2002). At this time, the Board also notes that it is cognizant of the ruling in Bryant v. Shinseki, 23 Vet. App. 488 (2010), that 38 C.F.R. § 3.103(c)(2) requires that the RO official or VLJ who conducts a hearing fulfill two duties to comply with the above the regulation. These duties consist of (1) the duty to fully explain the issues and (2) the duty to suggest the submission of evidence that may have been overlooked. The Board finds that this was done at the April 2013 Board hearing. Moreover, to the extent possible, VA has obtained the relevant evidence and information needed to adjudicate this appeal. Neither the Veteran nor his representative has asserted that VA failed to comply with 38 C.F.R. § 3.103(c)(2), nor has he identified any prejudice in the conduct of the April 2013 Board hearing. The Board has reviewed all the evidence in the Veteran's claims file. Although the Board has an obligation to provide adequate reasons and bases supporting this decision, there is no requirement that the evidence submitted by the appellant or obtained on his behalf be discussed in detail. Rather, the Board's analysis below will focus specifically on what evidence is needed to substantiate the claims and what the evidence in the claims file shows, or fails to show, with respect to the claims. See Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000) and Timberlake v. Gober, 14 Vet. App. 122, 128-30 (2000). New and Material Evidence The Veteran contends that he has esophageal cancer that was caused by Agent Orange (herbicide) exposure during his active service in Vietnam. The Veteran filed the instant claim for service connection for esophageal cancer in November 2008. In an April 2009 rating decision, the RO determined that new and material evidence had not been received to reopen the previously denied claim for service connection for esophageal cancer. The Veteran was notified of this decision by a letter dated in April 2009. As discussed below, the Board finds that during the year following notice of this rating decision, new and material evidence was received from the Veteran and his representative, and thus this evidence is considered as having been filed in connection with the November 2008 claim which was pending at the beginning of the appeal period. See 38 C.F.R. § 3.156(b). In an April 2010 rating decision, the RO determined that new and material evidence had been received to reopen the previously denied claim for service connection for esophageal cancer, and then denied the claim on the merits. A decision of the RO becomes final and is not subject to revision on the same factual basis unless a notice of disagreement is filed within one year of the notice of the decision. 38 U.S.C.A. § 7105; 38 C.F.R. §§ 20.302, 20.1103. If a claim of entitlement to service connection has been previously denied and that decision became final, the claim can be reopened and reconsidered only if new and material evidence is presented with respect to that claim. 38 U.S.C.A. § 5108; see also Manio v. Derwinski, 1 Vet. App. 140, 145 (1991). New evidence is defined as existing evidence not previously submitted to agency decisionmakers. Material evidence is defined as existing evidence that, by itself or when considered with previous evidence of record, relates to an unestablished fact necessary to substantiate the claim. New and material evidence can be neither cumulative nor redundant of the evidence of record at the time of the last prior final denial of the claim sought to be reopened, and must raise a reasonable possibility of substantiating the claim. 38 C.F.R. § 3.156(a). In Shade v. Shinseki, 24 Vet. App. 110, 118 (2010), the Court stated that when determining whether the submitted evidence meets the definition of new and material evidence, VA must consider whether the new evidence could, if the claim were reopened, reasonably result in substantiation of the claim. Id. at 118. Thus, pursuant to Shade, evidence is new if it has not been previously submitted to agency decisionmakers and is material if, when considered with the evidence of record, it would at least trigger VA's duty to assist by providing a medical opinion, which might raise a reasonable possibility of substantiating the claim. Id. The Court has interpreted the language of 38 C.F.R. § 3.156(a) as creating a low threshold, and viewed the phrase "raises a reasonable possibility of substantiating the claim" as "enabling rather than precluding reopening." Shade v. Shinseki, 24 Vet. App. 110 (2010). The Court emphasized that the regulation is designed to be consistent with 38 C.F.R. § 3.159(c)(4), which "does not require new and material evidence as to each previously unproven element of a claim." Id. In determining whether evidence is "new and material," the credibility of the new evidence must be presumed. Justus v. Principi, 3 Vet. App. 510, 513 (1992); Kutscherousky v. West, 12 Vet. App. 369, 371 (1999) (per curium). See also Duran v. Brown, 7 Vet. App. 216 (1994) (indicating that Justus does not require the VA Secretary to consider the patently incredible to be credible). Courts have held that 38 C.F.R. § 3.156(b) requires that VA evaluate submissions received during the year following notice of a rating decision to determine whether they contain new and material evidence, even if the new submission may support a new claim. See Bond v. Shinseki, 659 F.3d 1362, 1367-8 (Fed. Cir. 2011); Buie v. Shinseki, 24 Vet. App. 242, 251-52 (2010). The Veteran submitted his original claim for service connection for esophageal cancer in August 2007. He contended that he had esophageal cancer due to in-service exposure to Agent Orange. The RO denied entitlement to service connection for esophageal cancer in an October 2007 rating decision, finding that the Veteran's service treatment records were negative for esophageal cancer, and that there was no evidence linking his current esophageal cancer with service, including on a presumptive basis based on herbicide exposure during his service in Vietnam. The RO properly notified the Veteran of this denial. The Veteran did not file a notice of disagreement with the October 2007 rating decision and no new and material evidence pertinent to the issue was physically or constructively associated with the claims folder within one year after the rating decision. See 38 C.F.R. § 3.156 (2013); Bond v. Shinseki, 659 F.3d 1362 (Fed. Cir. 2011); see also Buie v. Shinseki, 24 Vet. App. 242, 251-52 (2010). Thus, the October 2007 rating decision became final based on the evidence then of record. 38 U.S.C.A. §§ 7104, 7105 (West 2002); 38 C.F.R. §§ 3.104(a), 3.160(d), 20.200, 20.302, 20.1103, 20.1105 (2013). Evidence of record at the time of the prior final October 2007 rating decision included service treatment records that are negative for esophageal cancer, and private medical records and VA medical records reflecting that he was first diagnosed with esophageal adenocarcinoma in July 2007. Evidence of record at the time of the October 2007 rating decision also included the Veteran's lay statements contending that his esophageal cancer was due to herbicide exposure in service. Additional evidence received since the prior final October 2007 rating decision includes the Veteran's duplicative statements to the effect that his esophageal cancer was due to herbicide exposure in service. This evidence is duplicative, not new. Additional evidence submitted since the prior final October 2007 rating decision also includes private medical records from Dr. A. and Dr. C. that were received by VA in July 2009 and January 2010. In a July 2009 letter, Dr. A. stated that Agent Orange/herbicide exposure was a "possible cause" of the Veteran's esophageal adenocarcinoma, and in a January 2010 letter, Dr. C. opined that it was more likely than not that his esophageal cancer was related to his Agent Orange/herbicide exposure. Upon review of the record, the Board finds that some of the evidence received since the October 2007 rating decision is both new and material. Specifically, the claims file now contains medical evidence suggesting that the Veteran's esophageal cancer may be related to Agent Orange exposure during service. This evidence was not of record at the time of the prior final rating decision, and relates to an unestablished fact necessary to substantiate the claim, and raises a reasonable possibility of substantiating the claim. Thus, the claim is reopened. 38 U.S.C.A. § 5108; 38 C.F.R. § 3.156(a); Shade, supra. Governing Law and Regulations Regarding Service Connection Except as otherwise provided by law, a claimant has the responsibility to present and support a claim for benefits under laws administered by the Secretary. The Secretary shall consider all information and lay and medical evidence of record in a case before the Secretary with respect to benefits under laws administered by the Secretary. When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the Secretary shall give the benefit of the doubt to the claimant. 38 U.S.C.A. § 5107 (West 2002); see also Gilbert v. Derwinski, 1 Vet. App. 49, 53 (1990). To deny a claim on its merits, the evidence must preponderate against the claim. Alemany v. Brown, 9 Vet. App. 518, 519 (1996), citing Gilbert, 1 Vet. App. at 54. Service connection is granted for disability resulting from disease or injury incurred in or aggravated by active military service in the line of duty. 38 U.S.C.A. §§ 1110, 1131; 38 C.F.R. § 3.303(a). Service connection may be granted for any disease diagnosed after discharge when the evidence, including that pertinent to service, establishes the disease was incurred in service. 38 C.F.R. § 3.303(d). Service connection may only be awarded to an applicant who has disability existing on the date of application, not for past disability. Degmetich v. Brown, 8 Vet. App. 208 (1995); 104 F.3d 1328, 1332 (1997)); but see McClain v. Nicholson, 21 Vet. App. 319, 321 (2007) (further clarifying that this requirement of current disability is satisfied when the claimant has the disability at the time the claim for VA disability compensation is filed or during the pendency of the claim and that a claimant may be granted service connection even though the disability resolves prior to VA's adjudication of the claim). Malignant tumors are considered chronic, per se, and therefore will be presumed to have been incurred in or aggravated by service if manifested to a compensable degree (meaning to at least 10-percent disabling) within one year of separation from service. This presumption, however, is rebuttable by affirmative evidence to the contrary. 38 U.S.C.A. §§ 1101, 1112, 1113, 1137; 38 C.F.R. §§ 3.307, 3.309(a). Diseases associated with exposure to certain herbicide agents used in support of military operations in the Republic of Vietnam during the Vietnam era will be presumed to have been incurred in service. 38 U.S.C.A. § 1116(a)(1); 38 C.F.R. § 3.307(a)(6). This presumption requires exposure to an herbicide agent and manifestation of the disease to a degree of 10 percent or more within the time period specified for each disease. 38 C.F.R. § 3.307(a)(6)(ii). Furthermore, even if a Veteran does not have a disease listed at 38 C.F.R. § 3.309(e), it will be presumed that he was exposed to herbicides if he served in Vietnam between January 9, 1962 and May 7, 1975 (i.e., during the Vietnam era), unless there is affirmative evidence establishing he was not exposed to any such agent during that service. 38 U.S.C.A. § 1116(f); 38 C.F.R. § 3.307(a)(6)(iii). The diseases presumptively associated with Agent Orange exposure include chloracne or other acneform disease consistent with chloracne, Type II Diabetes, Hodgkin's disease, ischemic heart disease, all chronic B-cell leukemias, multiple myeloma, Non-Hodgkin's lymphoma, acute and subacute peripheral neuropathy, Parkinson's disease, porphyria cutanea tarda, prostate cancer, respiratory cancers (cancer of the lung, bronchus, larynx, or trachea), AL amyloidosis, and soft-tissue sarcoma. 38 C.F.R. § 3.309(e) (2013). The Agent Orange Act of 1991 requires that when the Secretary determines that a presumption of service connection based on herbicide exposure is not warranted for health outcomes, he must publish a notice of that determination, including an explanation of the scientific basis for the decision. The Secretary's determination must be based on consideration of reports of the National Academy of Sciences (NAS) and all other sound medical and scientific information and analysis available to the Secretary. 38 U.S.C.A. § 1116 (b) and (c). In September 2011, the National Academy of Sciences (NAS) issued Veterans and Agent Orange: Update 2010 (Update 2010). The Secretary of VA has determined, based upon Update 2010 and prior NAS reports, that a presumption of service connection based on exposure to herbicides in the Republic of Vietnam is not warranted for the following health outcomes: hypertension, cancers of the oral cavity (including lips and tongue), pharynx (including tonsils), or nasal cavity (including ears and sinuses), cancers of the pleura, mediastinum, and other unspecified sites within the respiratory system and intrathoracic organs, cancers of the digestive organs (esophageal cancer; stomach cancer; colorectal cancer (including small intestine and anus), hepatobiliary cancers (liver, gallbladder and bile ducts), and pancreatic cancer), bone and joint cancer, melanoma, non-melanoma skin cancer (basal cell and squamous cell), breast cancer, cancers of reproductive organs (cervix, uterus, ovary, testes, and penis; excluding prostate), urinary bladder cancer, renal cancer (kidney and renal pelvis), cancers of brain and nervous system (including eye), endocrine cancers (including thyroid and thymus), leukemia (other than all chronic B-cell leukemias including chronic lymphocytic leukemia and hairy cell leukemia), cancers at other and unspecified sites (other than those as to which the Secretary has already established a presumption), reproductive effects (including infertility, spontaneous abortion other than after paternal exposure to TCDD; and - in offspring of exposed people - neonatal death, infant death, stillborn, low birth weight, birth defects (other than spina bifida), and childhood cancer (including acute myeloid leukemia)), neurobehavioral disorders (cognitive and neuropsychiatric), neurodegenerative diseases (including amyotrophic lateral sclerosis, but excluding Parkinson's disease), chronic peripheral nervous system disorders (other than early-onset peripheral neuropathy), respiratory disorders (wheeze or asthma, chronic obstructive pulmonary disease, and farmer's lung), gastrointestinal, metabolic, and digestive disorders (including changes in liver enzymes, lipid abnormalities, and ulcers), immune system disorders (immune suppression, allergy, and autoimmunity), circulatory disorders (other than ischemic heart disease), endometriosis, effects on thyroid homeostasis, hearing loss, eye problems; and bone conditions. See 59 Fed. Reg. 341 (Jan. 4, 1994); 61 Fed. Reg. 41,442 (Aug. 8, 1996); 64 Fed. Reg. 59,232 (Nov. 2, 1999); 67 Fed. Reg. 42,600 (June 24, 2002); 68 Fed. Reg. 27,630 (May 20, 2003); 72 Fed. Reg. 32,395 (June 12, 2007); 75 Fed. Reg. 32,540 (June 8, 2010); 75 Fed. Reg. 81,332 (Dec. 27, 2010). In interpreting sections 1110 and 1131 of the statute and section 3.303(a) of the regulations, the United States Court of Appeals for the Federal Circuit (Federal Circuit Court) held that a three-element test must be satisfied in order to establish entitlement to service connection. Specifically, the evidence must show (1) the existence of a current disability; (2) in-service incurrence or aggravation of a relevant disease or an injury; and (3) a causal relationship between the current disability and the disease or injury incurred or aggravated during service - the so-called "nexus" requirement. Walker v. Shinseki, 708 F.3d. 1331, 1333 (Fed. Cir. 2013) (citing Holton v. Shinseki, 557 F.3d 1363, 1366 (Fed. Cir. 2009) (quoting Shedden v. Principi, 381 F.3d 1163, 1166-67 (Fed. Cir. 2004))). Under 38 C.F.R. § 3.303(b), claims for certain chronic diseases - namely those listed in 38 C.F.R. § 3.309(a) - benefit from a somewhat more relaxed evidentiary standard. See Walker, 708 F3d. at 1339 (holding that "[t]he clear purpose of the regulation is to relax the requirements of § 3.303(a) for establishing service connection for certain chronic diseases."). When a chronic disease is established during active service, then subsequent manifestations of the same chronic disease at any later date, however remote, will be entitled to service connection, unless clearly attributable to causes unrelated to service ("intercurrent causes"). 38 C.F.R. § 3.303(b). In order to establish the existence of a chronic disease in service, the evidence must show a combination of manifestations sufficient to identify the disease entity, and sufficient observation to establish chronicity at the time, as distinguished from merely isolated findings or a diagnosis including the word "chronic." Id. Thus, the mere manifestation during service of potentially relevant symptoms (such as joint pain or abnormal heart action in claims for arthritis or heart disease, for example) does not establish a chronic disease at that time unless the identity of the disease is established and its chronicity may not be legitimately questioned. Id. If chronicity in service is not established, then a showing of continuity of symptoms after discharge is required to support the claim. Id. The Federal Circuit Court noted that the requirement of showing a continuity of symptomatology after service is a "second route by which a Veteran can establish service connection for a chronic disease" under subsection 3.303(b). Walker, 708 F3d. at 1336. Showing a continuity of symptoms after service itself "establishes the link, or nexus" to service and also "confirm[s] the existence of the chronic disease while in service or [during the] presumptive period." Id. (holding that section 3.303(b) provides an "alternative path to satisfaction of the standard three-element test for entitlement to disability compensation"). Significantly, the Federal Circuit Court indicated that showing a continuity of symptomatology after service is a lesser evidentiary burden than the nexus requirement of the three-part test discussed above: "The primary difference between a chronic disease that qualifies for § 3.303(b) analysis, and one that must be tested under § 3.303(a), is that the latter must satisfy the 'nexus' requirement of the three-element test, whereas the former benefits from presumptive service connection . . . or service connection via continuity of symptomatology" (emphasis added). Id. at 1339. Not all diseases that may be considered "chronic" from a medical standpoint qualify for the relaxed evidentiary standard under section 3.303(b). Rather, the Federal Circuit Court held that this subsection only applies to the specific chronic diseases listed in 38 C.F.R. § 3.309(a). Id. at 1338-40. Thus, if the claimant does not have one of the chronic diseases enumerated in section 3.309(a), then the more relaxed continuity-of-symptomatology standard does not apply, and "medical nexus of a relationship between the condition in service and the present condition is required." Id. at 1338. Malignant tumors are such a chronic condition under 38 C.F.R. § 3.309(a), but sleep apnea is not. Service connection may be established either by showing direct service incurrence or aggravation or by using applicable presumptions, if available. Combee v. Brown, 34 F.3d 1039, 1043 (Fed. Cir. 1994). Service connection may also be granted for disability which is proximately due to or the result of service-connected disability. 38 C.F.R. § 3.310(a); see Allen v. Brown, 7 Vet. App. 439 (1995) (en banc). An increase in severity of a non-service-connected disorder that is proximately due to or the result of a service-connected disability, and not due to the natural progress of the non-service-connected condition, will be service connected. Aggravation will be established by determining the baseline level of severity of the non-service-connected condition and deducting that baseline level, as well as any increase due to the natural progress of the disease, from the current level. 38 C.F.R. § 3.310(b). When determining service connection, all theories of entitlement - direct, presumptive and secondary, must be considered. Szemraj v. Principi, 357 F.3d 1370, 1371 (Fed. Cir. 2004). Lay evidence can be competent and sufficient to establish a diagnosis of a condition when: (1) a layperson is competent to identify the medical condition, (e.g., a broken leg, separated shoulder, pes planus (flat feet), varicose veins, the tinnitus (ringing in the ears), etc.), (2) the layperson is reporting a contemporaneous medical diagnosis, or (3) lay testimony describing symptoms at the time supports a later diagnosis by a medical professional. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). Medical evidence is not always or categorically required when the determinative issue involves either medical diagnosis or etiology, but rather such issue may, depending on the facts of the case, be established by competent and credible lay evidence under 38 U.S.C.A. § 1154(a). See Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). In essence, lay testimony is competent when it regards the readily observable features or symptoms of injury or illness and "may provide sufficient support for a claim of service connection." Layno v. Brown, 6 Vet. App. 465, 469 (1994); see also 38 C.F.R. § 3.159(a)(2). A determination as to whether medical evidence is needed to demonstrate that a Veteran presently has the same condition he or she had in service or during a presumptive period, or whether lay evidence will suffice, depends on the nature of the Veteran's present condition (e.g., whether the Veteran's present condition is of a type that requires medical expertise to identify it as the same condition as that in service or during a presumption period, or whether it can be so identified by lay observation). Barr v. Nicholson, 21 Vet. App. 303, 310 (2007). Any issue material to the determination is resolved in the Veteran's favor. 38 U.S.C.A. § 5107; 38 C.F.R. § 3.102. The claim is granted if the evidence is favorable to the claim or in relative equipoise, meaning about evenly balanced for and against his claim. If the preponderance of the evidence, instead, is against the claim, then it must be denied. See Gilbert v. Derwinski, 1 Vet. App. 49 (1990); Dela Cruz v. Principi, 15 Vet. App. 143, 148-49 (2001). Analysis Esophageal Cancer As noted above, the Veteran's original claim for service connection for esophageal cancer was denied in an unappealed October 2007 rating decision. Since the claim has been reopened, service connection for esophageal cancer is to be reviewed based on all the evidence of record. Manio, supra. The Board has considered whether adjudicating this claim on a de novo basis at this time would unduly prejudice the Veteran. See Hickson v. Shinseki, 23 Vet. App. 394 (2010) (Generally, where the Board reopens a claim but the RO did not, the case must be remanded for RO consideration unless there is a waiver from the appellant or no prejudice would result from the Board's immediate readjudication of the claim.). Here, the RO has reopened this claim and considered it on its merits. The Veteran has been provided the pertinent laws and regulations regarding establishing his entitlement to service connection for this claimed disability and given the opportunity to review the evidence of record and submit arguments in support of his claim. His arguments have focused squarely on this issue of service connection, not whether new and material evidence has been submitted, particularly since his claim was reopened. Therefore, the Board may proceed with the readjudication of his claim on its underlying merits without fear of predjudicing him. See Sutton v. Brown, 9 Vet. App. 553 (1996); Bernard v. Brown, 4 Vet. App. 384 (1993). The Veteran contends that he incurred esophageal cancer as a result of herbicide exposure during service in Vietnam and Guam. Private medical records reflect that he was diagnosed with adenocarcinoma of the esophagus in July 2007, which was subsequently treated, and that he had this disability during the pendency of this appeal. Thus, a current disability of esophageal cancer is shown, and resolution of his appeal turns on whether the esophageal cancer is attributable to his military service. See McClain, supra; Watson v. Brown, 4 Vet. App. 309, 314 (1993) ("A determination of service connection requires a finding of the existence of a current disability and a determination of a relationship between that disability and an injury or a disease incurred in service."). See also Maggitt v. West, 202 F.3d 1370, 1375 (Fed. Cir. 2000). The Veteran's service personnel records and STRs reflect that he served in the Republic of Vietnam during the Vietnam era, and thus he is presumed to have been exposed to herbicides during service. His STRs are entirely negative for cancer, including esophageal cancer. On separation medical examination in September 1968, the Veteran's throat, abdomen, and viscera were normal. In a September 1968 report of medical history, the Veteran denied tumor, growth, cyst, cancer, chest pain or pressure, frequent indigestion, and stomach, liver or intestinal trouble. In August 1983, the Veteran filed claims for multiple other disabilities, but did not file a claim for service connection for esophageal cancer or any esophageal disorder. Private medical records dated in the 1980s reflect that the Veteran smoked one pack of cigarettes per day. In April 1987, he reported that he was a social drinker and stopped smoking one and one-half years ago. He complained of significant stress at work, as well as what he described as esophagitis. Current medications included Tagamet. The physician diagnosed PTSD due to his work. In February 1988, the Veteran complained of intermittent chest pain; the diagnostic assessment was costochondritis, and the physician, Dr. N., noted that he also had a diagnosis of reflux esophagitis. A May 1994 VA barium swallow study shows that the Veteran's mucosal pattern of the esophagus was within normal limits. There was mild hiatal hernia without reflux. The diagnostic impression was no duodenal ulcer, spasm in the duodenal bulb, coarse edematous mucosal pattern in the duodenal bulb and second portion of the duodenum which could be due to duodenitis. A subsequent VA clinic note reflects a diagnostic impression of hypertension, hiatal hernia with old history of gastroesophageal reflux disease (GERD) and more recently duodenitis, anxiety and agoraphobia. In July 1995, the Veteran filed a claim for service connection for another disability (PTSD), but did not file a claim for service connection for esophageal cancer or any esophageal disorder. On VA general medical examination in September 1995, the Veteran reported that he retired from the U.S. Postal Service due to stress. It was noted that in 1983 he was reportedly found to have a hiatal hernia with reflux esophagitis, and he currently took appropriate medication with good relief. On examination of the abdomen, there were no masses or tenderness. The pertinent diagnoses were anxiety disorder with agoraphobia and hiatal hernia with reflux esophagitis. An April 2007 private medical record from Dr. C. reflects that the Veteran denied gastrointestinal symptoms, including heartburn, difficulty swallowing, pain on swallowing, and acid reflux. He had no weight loss and no hematemesis. In early July 2007, the Veteran complained of difficulty swallowing since the prior Friday. He had no heartburn as this was controlled by medication. A barium swallow was planned. Private medical records from other physicians dated in July 2007 reflect that an upper gastrointestinal series showed a moderate-sized polypoid mass involving the distal esophagus. In July 2007, he reported a history of progressive dysphagia over the past few months. He underwent an endoscopy which showed an abnormal esophagus. Biopsies showed esophageal cancer. On oncology consult in August 2007, Dr. E. noted that in late June 2007, the Veteran had a sense of slow transit through his esophagus with mild discomfort. Dr. E. noted that he smoked approximately one pack of cigarettes per day from age 17 to 34. The diagnostic impression was that the Veteran presented with dysphagia, odynophagia and weight loss, who had a mass in the esophagus. A biopsy of the mass revealed moderate to poorly-differentiated adenocarcinoma. The Veteran subsequently underwent esophagectomy and chemoradiation. The Board has reviewed the voluminous evidence of record, and finds, for the reasons and bases discussed below, that the preponderance of the evidence is against the claim. The Board notes that esophageal cancer is not among the listed conditions subject to presumptive service connection based on herbicide exposure under 38 C.F.R. § 3.309(e). Significantly, the Secretary of VA has explicitly determined, based upon NAS studies including Update 2010, that a presumption of service connection based on exposure to herbicides in the Republic of Vietnam is not warranted for esophageal cancer. Moreover, there is no evidence that a malignant tumor of the esophagus was manifested to a compensable degree within the first post-service year, and thus presumptive service connection is also not warranted under 38 C.F.R. § 3.309(a). But this only precludes presumptive service connection, not also the possibility of the Veteran establishing this necessary linkage for service connection with proof of direct causation. See Stefl v. Nicholson, 21 Vet. App. 120 (2007); see also Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). The Veteran has submitted a May 1990 report by Admiral Zumwalt that was submitted to the Secretary of VA, regarding the association between adverse health effects and exposure to Agent Orange. This document does not tend to show that the Veteran's current esophageal cancer is related to Agent Orange exposure, and does not amount to competent evidence of causality. See Sacks v. West, 11 Vet. App. 314 (1998); Beausoleil v. Brown, 8 Vet. App. 459 (1996). In a July 2009 letter, T.A., MD, of Dana-Farber Cancer Institute, stated that he was treating the Veteran for esophageal carcinoma. He stated, "At this time, it is unknown how [the Veteran] contracted this disease. One possible cause is [the Veteran's] exposure to Agent Orange and other herbicides while in combat during the Vietnam War." This statement, by its own language, is nothing more than equivocal speculation, which is also unsupported by an adequate rationale, and it lacks probative value. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008); Beausoleil v. Brown, 8 Vet. App. 459 (1996). In a January 2010 letter, R.G.C., D.O., said that the Veteran was his patient and was status post esophageal cancer. He opined that, "...in my medical opinion it is more likely then [sic] not his Esophageal Cancer is related to his exposure to Agent Orange and other Herbicides while he was serving in Vietnam." The Board finds that this statement is completely unsupported by any rationale, and it therefore lacks probative value. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295 (2008). Moreover, the Board finds that the probative value of Dr. C.'s unsupported medical opinion is outweighed by the recent NAS studies cited above. The VA Secretary, under the authority of the Agent Orange Act of 1991, has determined that there is no positive association between exposure to herbicides and cancers of the digestive organs, including esophageal cancer. See Notice, 77 Fed. Reg. 47,924 (Aug. 10, 2012). This determination is based on various reports published by National Academy of Sciences (NAS) in which NAS reviews and summarizes the scientific evidence concerning the association between exposure to herbicides and various health outcomes, and the Board finds that these NAS reports are highly probative. In July 2013, the Veteran submitted multiple Disability Benefits Questionnaires completed by different doctors. These forms collectively show that the Veteran had esophageal cancer which was resected, and that the Veteran now has very significant health problems resulting from the cancer and subsequent treatment. These documents do not provide any opinion as to the etiology of the esophageal cancer, and do not tend to show that it is related to service. There are no relevant post-service medical records regarding esophageal cancer until 2007, so for nearly 30 years after the Veteran's separation from service. The evidence does not reflect, and the Veteran does not contend, that he had continuous esophageal cancer symptoms from service until 2007. See Maxson v. West, 12 Vet. App. 453, 459 (1999), affirmed sub nom. Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000) (ruling that a prolonged period without medical complaint can be considered, along with other factors, as evidence of whether an injury or a disease was incurred in service resulting in any chronic or persistent disability). Although the Veteran was treated for gastric reflux since at least the 1980s, esophageal cancer was not diagnosed until 2007, and the Veteran's esophagus was within normal limits on VA barium swallow study in May 1994. At that time, there was a mild hiatal hernia without reflux. The Board finds that this is highly probative competent medical evidence weighing against the claim that he had esophageal cancer that began in service. After reviewing all the relevant lay and medical evidence, the Board finds that the weight of this evidence (the most probative of it) indicates the Veteran has not experienced continuous esophageal cancer symptoms since service. The Board recognizes that the Veteran, himself, has asserted that esophageal cancer was caused by herbicide exposure in service and that, in some cases, such lay evidence is competent and credible on the issues of diagnosis and etiology. Jandreau, supra. Esophageal cancer, however, is a medically complex condition that is not readily amenable to mere lay diagnosis or probative comment regarding its etiology. See Barr, 21 Vet. App. at 307; Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). See also Colantonio v. Shinseki, 606 F.3d 1378, 1382 (Fed. Cir. 2010) (recognizing that in some cases lay testimony "falls short" in proving an issue that requires expert medical knowledge); Waters v. Shinseki, 601 F.3d 1274, 1278 (Fed. Cir. 2010) (concluding that a Veteran's lay belief that his schizophrenia aggravated his diabetes and hypertension was not of sufficient weight to trigger the Secretary's duty to seek a medical opinion on the issue). Therefore, in weighing the Veteran's lay assertions and the unsupported medical opinion of Dr. C. against the service treatment records, post-service medical records, and the Secretary's Notice, the Board finds the latter are more probative as to the determinative issue of causation. See Guerrieri v. Brown, 4 Vet. App. 467, 473 (1993) ("the probative value of medical opinion evidence is based on the medical expert's personal examination of the patient, the physician's knowledge and skill in analyzing the data, and the medical conclusion the physician reaches.... As is true with any piece of evidence, the credibility and weight to be attached to these opinions [are] within the province of the [Board as] adjudicators. . ."); Madden v. Gober, 125 F.3d 1477, 1481 (Fed. Cir. 1997) (holding that the Board is entitled to discount the credibility of evidence in light of its own inherent characteristics and its relationship to other items of evidence). As there is no evidence in the service treatment records to support direct causation, no manifestation of the esophageal cancer within one year of separation from service to support presumptive causation, and insufficient evidence to alternatively support presumptive service connection based on herbicide exposure during the Veteran's Vietnam service, the Board finds that the weight of the evidence is against linking his esophageal cancer to his military service. For these reasons and bases, the Board finds that the preponderance of the competent and credible evidence establishes that the Veteran's esophageal cancer developed many years after service, and that this cancer was not caused by any incident of his service - including his presumed exposure to herbicides (the dioxin in Agent Orange). Thus, there is no basis for granting service connection for this disability. Finally, although the Veteran has submitted copies of Board decisions regarding other Veterans, and argues that these decisions have precedential value in his case, the Board must disagree. Accordingly, the Board finds that the preponderance of the evidence is against the Veteran's claim for service connection for esophageal cancer, there is no reasonable doubt to resolve in his favor, and this claim must be denied. 38 U.S.C.A. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). Sleep Apnea The Veteran contends that he has sleep apnea secondary to his service-connected PTSD. VA medical records dated in 2006 and 2007 reflect diagnosis and treatment for obstructive sleep apnea (OSA). Although the Veteran currently has only minimal symptoms from sleep apnea (see March 2012 VA treatment note), competent medical evidence of record shows that he has had a diagnosis and symptoms of this disorder during the pendency of the appeal, and that he still has a diagnosis of this disorder. Thus, a current sleep apnea disability is shown, and resolution of his appeal turns on whether his sleep apnea is attributable to his military service or to a service-connected disability. See McClain, supra; Watson, supra. His STRs are entirely negative for sleep apnea. On separation medical examination in September 1968, the Veteran's nose, sinuses, mouth, throat, lungs and chest were normal. In a September 1968 report of medical history, the Veteran denied frequent trouble sleeping. Post-service medical records reflect extensive treatment for psychiatric disorders with associated sleep impairment, but are negative for a diagnosis of sleep apnea until 2006. A May 2006 VA neurology note reflects that the Veteran reported that he snored, and his wife said he looked like he was not breathing. He said he easily fell asleep during the day, and never felt rested when he awoke in the morning. He was diagnosed with sensorimotor axonal polyneuropathy and questionable obstructive sleep apnea (OSA). Polysomnography studies were conducted in June 2006 and in November 2006. The diagnostic impression was positional and REM-related OSA - hypopnea. The examiner recommended use of CPAP, weight loss, and evaluation of his medications, with respect to the possibility that his medications were affecting sleepiness, including amitriptyline, clonazepam, and gabapentin, although his doses of these medications were not high. A February 2007 sleep study was performed for CPAP titration. During the study, CPAP was titrated to a high level, but was inadequate to eliminate obstructive events during non-REM sleep. The Veteran filed his initial claim for service connection for sleep apnea in January 2007, claiming it was secondary to service-connected PTSD. In a June 2007 statement, he said his primary care physician told him that this was the case. He said his sleep apnea problem had been ongoing since he was diagnosed with PTSD and probably longer. By a letter dated in April 2007, the Veteran's treating VA physician stated that the Veteran was being followed for multiple medical conditions including OSA. An April 2008 VA pulmonary/sleep clinic note reflects that the Veteran had positional OSA and was seen for follow-up. It was noted that he had recently undergone esophagectomy and gastric pull-through, with chemotherapy and radiation. He was not using CPAP but had to sleep on his back because of pain when he slept on his side. The pertinent diagnostic impression was positional OSA status post recent esophagectomy. The examiner noted that the Veteran had excessive daytime sleepiness and insomnia, and had lost significant weight, from 212 to 174 pounds. He was sleeping exclusively on his back and he was still symptomatic. A March 2009 VA pulmonary/sleep clinic note reflects that the Veteran was taking clonazepam and lamictal for PTSD and other psychiatric disorders, and now wanted to try CPAP. His wife said he snored but had no apneas. The diagnostic assessment was OSA, and he was still having snoring reflux and arousals at night. On VA compensation examination in January 2012, the Veteran reported that his OSA symptoms began in the early 2000s, and that his wife told him he stopped breathing when asleep and snored loudly. He also noted daytime fatigue. The examiner noted that in the early 2000s he weighed 195-200, and previously in the military he weighed in the 170s. A 2006 sleep study showed that he weighed 212 pounds, and underwent polysomnography which showed no obstructive apneas, but occasional obstructive hypopnea. During REM sleep in the side position there was severe sleep fragmentation due to obstructive events with a REM AHI of 55 per hour. He underwent CPAP titration. He developed esophageal cancer in July 2007, and had a total esophagectomy in January 2008. The examiner noted that he quit cigarettes 28 years ago, after smoking 1.5 to 2 packs per day, and also quit alcohol at that time. He noted that since his surgery he had weight loss, and currently weighed 175 pounds. He slept in a position of 45 degrees due to reflux symptoms which made him choke. His wife slept in another room and had not noticed loud snoring/or cessation of breathing. After an examination, the diagnostic impression was past sleep apnea syndrome. The examiner noted that the Veteran had been on sedating medication that could relax the upper airway (clonazepam) for PTSD, and that this could worsen OSA, but he had no current symptoms of sleep apnea. He lost weight since his surgery and this was likely responsible. The examiner opined that the Veteran's previous OSA was not related to his previous service, but that more likely than not, the medications for PTSD worsened the condition when it was diagnosed in 2006. He concluded that the Veteran may not have significant sleep apnea syndrome at present. In an April 2012 addendum, the examiner stated that he had reviewed the claims file in providing his medical opinion. A March 2012 VA pulmonary sleep clinic note reflects that the Veteran had a past diagnosis of OSA, and was referred for re-evaluation after a major weight loss. He noted that on polysomnogram in November 2006, at a weight of 212, he had positional and REM-related OSA. As of his last visit, he had major weight loss, and was no longer using CPAP. Today, the Veteran reported that he had no concerns about his sleep, and he slept at greater than 45 degrees upright due to reflux related to his esophageal resection and gastric reconstruction due to esophageal cancer in 2008. He had nocturnal GERD symptoms only about once a month. He no longer snored and felt that his sleep was refreshing. He denied significant daytime sleepiness. The diagnostic assessment was that based on the symptoms and interim weight loss, it is unlikely that the Veteran has significant residual OSA symptoms. The examiner noted that he considered GERD as a possible OSA symptom, but it was easily controlled at night with omeprazole. He concluded that the Veteran did have a diagnosis of residual sleep apnea, but currently had no symptoms. As to the question of sedating effects of PTSD medications, the Veteran now has no symptoms, and therefore the percentage assigned to these symptoms from sedating medication would be 0 percent. At his April 2013 Board hearing, the Veteran testified that he was previously diagnosed with sleep apnea, but that because of his very significant post-surgical residuals from his esophageal cancer treatment, he could no longer lie flat to sleep. He said that his doctor told him that he did not have sleep apnea anymore. The evidence does not reflect, and the Veteran does not contend, that symptoms from sleep apnea have been continuous since service. Rather, he and his representative have contended that his sleep apnea was caused or aggravated by his service-connected PTSD. After a review of the evidence of record, the Board finds that there is no probative evidence linking the Veteran's currently diagnosed sleep apnea with service. However, the Board finds that the medical and lay evidence concerning the determinative issue of whether the Veteran's current sleep apnea (however minimal in degree) was permanently aggravated by the medication for his service-connected PTSD is at least in relative equipoise, i.e., about evenly balanced for and against his claim. The competent and credible evidence suggests that the condition persists but it is minimized due to his sleeping position that is required by his post-surgical residuals from another condition. Consequently, resolving all reasonable doubt in his favor concerning the origin of his sleep apnea, the Board finds that service connection is warranted for this disability on the basis of aggravation. 38 U.S.C.A. § 5107(b); 38 C.F.R. §§ 3.102, 3.310; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). An "absolutely accurate" determination of etiology is not a condition precedent to granting service connection, nor is "definite" or "obvious" etiology; this need only be an as likely as not proposition, which in this instance it is. See Alemany v. Brown, 9 Vet. App. 518, 519 (1996). ORDER The claim for service connection for esophageal cancer is reopened, and the claim is granted to this extent only. Entitlement to service connection for esophageal cancer is denied. Entitlement to service connection for sleep apnea secondary to service-connected PTSD is granted on the basis of aggravation. REMAND Regarding the claim for entitlement to special monthly compensation (SMC) based on loss of use of creative organ, the Board remanded this issue in September 2011, finding that the Veteran's January 2007 claim for entitlement to SMC based on loss of use of creative organ was an inferred claim for entitlement to service connection for erectile dysfunction (E.D.), and referring that issue to the AMC/RO for appropriate action. The Board also found that that issue was inextricably intertwined with the SMC issue on appeal. The AMC/RO was asked to adjudicate the issue of entitlement to service connection for E.D. in the first instance. It does not appear that this was done. When any action required by a remand is not undertaken, or is taken in a deficient manner, appropriate corrective action should be undertaken. Stegall v. West, 11 Vet. App. 268 (1998). Hence, this issue must again be remanded for adjudication of the claim for service connection for E.D., and for subsequent readjudication of the SMC claim. In his initial January 2007 claim, the Veteran stated that he was recently diagnosed with diabetes and developed E.D. in the past year. The Board observes that in the June 2007 rating decision on appeal, service connection was not yet in effect for diabetes mellitus type II, and that service connection has since been established for this disability. In an April 2007 letter, the Veteran's treating VA physician stated that the Veteran's erectile dysfunction was multifactorial. In an October 2011 statement, the Veteran asserted that his "sugar problems" and peripheral neuropathy contributed to his erectile dysfunction. In a July 2012 statement, the Veteran's representative requested a VA compensation examination to determine whether the Veteran's E.D. and loss of use of a creative organ is related to service-connected PTSD and/or diabetes mellitus. The Veteran's representative also requested a remand for a VA examination to determine the etiology of this condition in a November 2012 written brief. At his April 2013 Board hearing, the Veteran and his representative contended that his erectile dysfunction was possibly related to diabetes mellitus, or to his cancer, or possibly to his medication. On remand, all of the relevant evidence should be considered, and additional development should be conducted as needed to adjudicate the issue of service connection for E.D., and readjudicate the issue of SMC based on loss of use of a creative organ. Pertinent medical records should be obtained. 38 U.S.C.A. § 5103A(c) (West 2002); see also Bell v. Derwinski, 2 Vet. App. 611 (1992) (VA medical records are in constructive possession of the agency, and must be obtained if the material could be determinative of the claim). Accordingly, the case is REMANDED for the following action: 1. With any necessary releases, obtain any relevant private or VA medical records of treatment for erectile dysfunction (E.D.) that are not already on file, and associate them with the paper claims file or with the Veteran's electronic Virtual VA folder. 2. The RO/AMC should complete any additional development deemed appropriate, including obtaining a VA medical opinion, and then adjudicate the intertwined issue of entitlement to service connection for erectile dysfunction including as secondary to his service-connected disabilities. 3. Thereafter, the RO/AMC should readjudicate the issue of entitlement to special monthly compensation based on loss of use of creative organ. If any of the claimed benefits remain denied, the RO/AMC must furnish a supplemental statement of the case (SSOC), before the claims file is returned to the Board, if otherwise in order. The appellant has the right to submit additional evidence and argument on the matter the Board has remanded. Kutscherousky v. West, 12 Vet. App. 369 (1999). This claim must be afforded expeditious treatment. The law requires that all claims that are remanded by the Board of Veterans' Appeals or by the United States Court of Appeals for Veterans Claims for additional development or other appropriate action must be handled in an expeditious manner. See 38 U.S.C.A. §§ 5109B, 7112 (West Supp. 2012). ______________________________________________ S. L. Kennedy Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs