Citation Nr: 1313043 Decision Date: 04/18/13 Archive Date: 05/02/13 DOCKET NO. 09-32 919 ) DATE ) ) On appeal from the Department of Veterans Affairs (VA) Regional Office (RO) in Manchester, New Hampshire THE ISSUE Entitlement to service connection for the cause of the Veteran's death. REPRESENTATION Appellant represented by: The American Legion WITNESS AT HEARINGS ON APPEAL Appellant ATTORNEY FOR THE BOARD Suzie S. Gaston, Counsel INTRODUCTION The Veteran served on active duty from November 1962 to June 1980; he died in March 2000. The appellant is his widow. This matter comes before the Board of Veterans' Appeals (Board) on appeal from a December 2007 rating decision, by the Manchester, New Hampshire RO. The appellant appeared and offered testimony at a hearing before a Decision Review Officer (DRO) at the RO in February 2009. A transcript of that hearing is of record. On August 3, 2010, the appellant testified at a hearing before the undersigned Veterans Law Judge sitting at the RO; a transcript of that hearing is of record. In September 2010, the Board remanded the case to the RO for further development. The appellant thereafter specifically withdrew from appeal her claim that service connection for the cause of the Veteran's death should be awarded on account of radiation exposure during service. The appellant was then provided a supplemental statement of the case (SSOC) in July 2011, in which the agency of original jurisdiction (AOJ) again denied the appellant's claim. In a November 2012 Board decision, the claim was reopened and remanded for further evidentiary development. A review of the record reflects substantial compliance with the Board's Remand directives. See Stegall v. West, 11 Vet. App. 268, 271 (1998). The VA Appeals Management Center (AMC) issued a supplemental statement of the case (SSOC) in February 2013. (This appeal has been advanced on the Board's docket pursuant to 38 C.F.R. § 20.900(c) (2012). 38 U.S.C.A. § 7107(a) (2) (West 2002).) FINDINGS OF FACT 1. The Veteran had active military service in the Republic of Vietnam during the Vietnam era. 2. The Veteran died in March 2000, at the age of 59; the immediate cause of death was reported as hypercapnic respiratory and pulmonary metastases from esophageal cancer, with coronary artery disease listed as a significant condition. 3. At the time of the Veteran's death he was not service connected for any disability. 4. The Veteran's fatal esophageal cancer with pulmonary metastasis did not originate in service or within one year of his discharge therefrom, and is not otherwise related to his military service, to include in-service exposure to Agent Orange. CONCLUSION OF LAW Service connection for the cause of the Veteran's death is not warranted. 38 U.S.C.A. §§ 1110, 1310, 5103, 5103A, 5107 (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.102, 3.159, 3.303, 3.312 (2012). REASONS AND BASES FOR FINDINGS AND CONCLUSION I. Duty to Notify and Assist The Veterans Claims Assistance Act of 2000 (VCAA) enhanced VA's duty to notify and assist claimants in substantiating their claims for VA benefits, as codified in pertinent part at 38 U.S.C.A. §§ 5103, 5103A (West 2002 & Supp. 2012); 38 C.F.R. §§ 3.159, 3.326(a) (2012). Upon receipt of a complete or substantially complete application for benefits, VA is required to notify the claimant of the information and evidence not of record that is necessary to substantiate the claim; to indicate which information and evidence VA will obtain and which information and evidence the claimant is expected to provide; and to request that the claimant provide any evidence in the claimant's possession that pertains to the claim. 38 U.S.C.A. § 5103(a); 38 C.F.R. § 3.159(b). The United States Court of Appeals for Veterans Claims (Court) has held that VCAA notice should be provided to a claimant before the initial RO decision on a claim. Pelegrini v. Principi, 18 Vet. App. 112 (2004). However, if VCAA notice is provided after the initial decision, such a timing error can be cured by subsequent readjudication of the claim, as in a statement of the case (SOC) or supplemental SOC (SSOC). Mayfield v. Nicholson, 20 Vet. App. 537, 543 (2006); Prickett v. Nicholson, 20 Vet. App. 370, 376 (2006). Additionally, in the context of a claim for Dependency and Indemnity Compensation (DIC) benefits, 38 U.S.C.A. § 5103(a) notice must include (1) a statement of the conditions, if any, for which a Veteran was service connected at the time of his or her death; (2) an explanation of the evidence and information required to substantiate a DIC claim based on a previously service-connected condition; and (3) an explanation of the evidence and information required to substantiate a DIC claim based on a condition not yet service connected. Hupp v. Nicholson, 21 Vet. App. 342, 352-53 (2007). In this case, VA satisfied its duty to notify by means of a letter dated in July 2007 from the RO to the appellant, which was issued prior to the RO decision in December 2007. An additional letter was issued in December 2010. Those letters informed the appellant of what evidence was required to substantiate the claim and of her and VA's respective duties for obtaining evidence. The Board finds that the content of those letters complied with the requirements of 38 U.S.C.A. § 5103(a) and 38 C.F.R. § 3.159(b) regarding VA's duty to notify. She was provided an opportunity at that time to submit additional evidence. In addition, the July 2011 and February 2013 SSOCs provided the appellant with an additional 60 days to submit additional evidence. Thus, the Board finds that the appellant has been afforded a meaningful opportunity to participate effectively in the processing of her claim. It also appears that all obtainable evidence identified by the appellant relative to her claim has been obtained and associated with the claims file, and that neither she nor her representative has identified any other pertinent evidence, not already of record, which would need to be obtained for a fair disposition of this appeal. It is therefore the Board's conclusion that the appellant has been provided with every opportunity to submit evidence and argument in support of her claim, and to respond to VA notice. In connection with the current appeal, an appropriate VA medical opinion has been obtained and service treatment records and post-service records have been obtained. We also note that the VA medical opinion was adequate. The clinician reviewed the history and the established clinical findings and presented reasons for his opinion. For the foregoing reasons, the Board concludes that all reasonable efforts were made by VA to obtain evidence necessary to substantiate the claim. The evidence of record provides sufficient information to adequately evaluate the claim, and the Board is not aware of the existence of any additional relevant evidence that has not been obtained or requested. No further assistance to the appellant with the development of evidence is required. 38 U.S.C.A. § 5103A (a) (2); 38 C.F.R. § 3.159(d). II. Background The record indicates that the Veteran served on active duty from November 1962 to June 1980, with service in Vietnam from August 1968 to August 1969. He was awarded the Bronze Star Medal, the National Defense Service Medal, the Vietnam Service Medal, the Vietnam Campaign Medal with 60 device, and the Vietnam Cross of Gallantry with Palm. The record reflects that the veteran died in March 2000, at the age of 59. A certificate of death, dated in March 2000, listed the immediate cause of death as hypercapnic respiratory and pulmonary metastases from esophageal cancer, with coronary artery disease listed as a significant condition. At the time of his death, the Veteran was not service connected for any disability. The Veteran's service treatment records (STRs) do not reflect any complaints, findings or diagnoses of any cancer, to include esophageal cancer. The appellant's initial claim for service connection for the cause of the Veteran's death (VA Form 21-534) was in March 2000. Submitted in support of the claim were private medical records from January 1997 to March 2000. These records show that the Veteran was treated for type 2 diabetes mellitus, coronary artery disease, esophageal cancer, and hypertension with dyslipidemia. The Veteran was treated for reflux esophagitis in March 1997; he was subsequently diagnosed with adenocarcinoma of the distal esophagus in April 1997. In August 1997, he underwent esophagogastrectomy. He subsequently underwent chemotherapy. In March 1999, the Veteran was seen with a non-productive cough and a CT scan of the chest showed both left and right lung abnormalities consistent with metastatic disease to the lung. He continued to receive chemotherapy. He subsequently succumbed to the metastatic disease on March 11, 2000. Of record is a statement from Dr. Kenneth M. Dolkart, dated in June 2007, who noted that the Veteran had a well-documented history of significant exposure to defoliants, including dioxin-containing agents such as Agent Orange. He also noted that the Veteran had documentation of significant exposure to these agents while in Vietnam and Thailand. Dr. Dolkart stated that the Veteran ultimately died of cancer of the esophagus, which he felt to be causally related to the dioxin exposure. In November 2007, the Veteran's claims folder was referred to a VA examiner for review and opinion pertaining to the question of whether there existed a relationship between the Veteran's death and his exposure to herbicides in Vietnam. The examiner noted that he reviewed the service treatment records and the private treatment reports, including the June 2007 statement from Dr. Dolkart; he also reviewed medical literature. The examiner noted the publication "Veterans and Agent Orange" (VAO) and noted that the committee responsible for VAO concluded that there was limited or suggestive evidence of "NO" association between exposure to the compounds of interest and gastrointestinal tumors. Therefore, the examiner concluded that, based on the extensive review of the medical literature and the report by the VAO, it was less likely as not that the Veteran died as a result of herbicide exposure. At the personal hearing in February 2009, the appellant's service representative maintained that the Veteran had no risk factor for the esophageal cancer except for his exposure to Agent Orange during his period of service in Vietnam. It was also argued that the November 2007 VA medical opinion was inadequate as it was based on outdated and not current medical literature. She requested another medical opinion using the latest research information on Agent Orange. Submitted in February 2009 was a copy of an internet article regarding Veterans and Agent Orange. Also submitted was information regarding Health Care and Benefits for Veterans Exposed to Agent Orange. In July 2009, the Veteran's claims folder was again referred to a VA examiner for review and opinion. The examiner stated that the Veteran's adenocarcinoma of the esophagus was not a result of his service in Southeast Asia. The examiner noted that the list of conditions recognized by VA dated in 2008 did not include either adenocarcinoma of the esophagus or Barrett's esophagus. The examiner further noted that there is no conclusive proof in the medical literature that these conditions are related to herbicide exposure. At her personal hearing in August 2010, the appellant's representative noted that coronary artery disease was listed as a significant condition contributing to the cause of death. He further noted that a science magazine, dated July 4, 2010, stated that studies indicate that dioxins might trigger or abet cancer development and possibly heart disease years after exposure. It was argued that the Veteran's private physician, Dr. Dolkart treated him for several years prior to his death; as such, it was argued that Dr. Dolkart's opinion should be afforded greater probative value than that of the VA examiner who had no knowledge of the Veteran's condition. Submitted at the hearing was a statement from Dr. James Gillett, professor of environmental toxicology. Dr. Gillett indicated that he was the founder of the Esophageal Awareness Association in 2002; and, he was acutely aware of the particular problems faced by Veterans in regards to treatment and disability compensation for this disability stemming from back to World War II and Korea. He noted that the VA had recently taken steps to improve this situation, particularly in light of the issues surrounding Agent Orange. He admitted that the evidence of causality had been and remained incomplete; nonetheless, Dr. Gillett stated that there had been a steady movement to encompass more and more of these cases within the circle of VA responsibility. Dr. Gillett noted that, in strong contrast to the United States, the death rates from esophageal cancers of all kinds are much higher in Southeast Asia, China and India, where they often are not just the leading cancer, but are the leading cause of death in many countries and communities. He further noted that, in spite of extensive efforts by both NIH/NCI and the health services of China, Japan, Korea, etc., we remained baffled by what might underlie that etiology; some claim that it was Agent Orange, but it could just as easily be the dust blowing from Central Asia. Dr. Gillett further noted that foods and their preparations, distributions of disease or organisms and spoilage, and fermented products may also be suspects. He strongly favor the presumption that one or more of these factor has some role in instigation of esophageal cancer in Asia and that service by our Veterans in that theater of operations should be recognized as probably contributing, whether a specific causal link exists or not. He strongly urged VA to do so for the Veteran in this case. In December 2012, the Veteran's claims folders were referred to a VA examiner for review and opinion regarding the cause of death. After a review of the claims file, the examiner opined that it was less likely as not that the Veteran's esophageal cancer was causally related to his presumed exposure to herbicides during his Vietnam service or to some other in-service event. The examiner stated that it has been established and acknowledged that the lung involvement was due to metastases from a primary gastrointestinal cancer and not a primary lung malignancy. The VA examiner stated that he disagreed with Dr. Dolkart's opinion because the American Cancer Society and other professional scientific organizations have extensively studied and evaluated scientific evidence regarding cancers of all types and their potential association to various toxic exposures, and they have not found a link between these exposures and any GI cancer. The examiner further explained that the statements made by Dr. Gillett appear to apply to indigenous residents of southeast Asia, China and India and not to any data specific to American Service members. He concluded that the scientific evidence to date would not support a link between Agent Orange exposure and any GI cancer, specifically esophageal cancer in the Veteran. The VA examiner also opined that it was less likely as not that the Veteran's coronary artery disease or diabetes mellitus contributed to his death in more than a casual way. The examiner noted that he had thoroughly reviewed the Veteran's private treatment reports in the claims file from the time of his diagnosis of esophageal cancer in April 1997 to his death in March 2000; during that period, there was no indication of any worsening of either condition, nor any new cardiac events that would have caused death or hastened his death. The examiner explained that the Veteran had extensive metastatic cancer to the lung with resultant respiratory failure that caused his death. The examiner stated that it was not likely that his diabetes or coronary artery disease or the combination of these two contributed substantially or materially to the Veteran's death--aiding or lending assistance to the production of death. In other words, if the Veteran did not have diabetes or coronary artery disease, death would have occurred around the same time due solely to the metastatic esophageal cancer. This condition alone was severe enough to cause the Veteran's death at the time death occurred. III. Analysis Service connection is warranted for disability "resulting from personal injury suffered or disease contracted in line of duty, or for aggravation of a preexisting injury suffered or disease contracted in line of duty." 38 U.S.C. §§ 1110 (wartime service), 1131 (peacetime service). To establish a right to compensation for a present disability, a claimant must show: "(1) the existence of a present disability; (2) in-service incurrence or aggravation of a disease or injury; and (3) a causal relationship between the present disability and the disease or injury incurred or aggravated during service"--the so-called "nexus" requirement. Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Holton v. Shinseki, 557 F.3d 1362 (2009). When a disease is first diagnosed after service, service connection may nevertheless be established by evidence demonstrating that the disease was in fact incurred during the Veteran's service. 38 C.F.R. § 3.303(d). In addition, service connection may be granted for a chronic disease, including malignant tumors, if manifested to a compensable degree within the prescribed presumptive period-one year following separation from service. This presumption is rebuttable by affirmative evidence to the contrary. 38 U.S.C.A. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309. Service connection for the cause of a Veteran's death may be granted when a disability incurred in or aggravated by service either caused or contributed substantially or materially to the Veteran's death. For a service-connected disability to be the cause of death, it must singly, or with some other condition, be the immediate or underlying cause of death, or be etiologically related. For a service-connected disability to constitute a contributory cause, it is not sufficient to show that it casually shared in producing death, but rather it must be shown that it contributed substantially or materially; that it combined to cause death; that it aided or lent assistance to the production of death. It must be shown that there was a causal connection. U.S.C.A. § 1310; 38 C.F.R. § 3.312. Generally, minor service-connected disabilities, particularly those of a static nature or not materially affecting a vital organ, would not be held to have contributed to death primarily due to unrelated disability. Service-connected diseases or injuries involving active processes affecting vital organs should receive careful consideration as a contributory cause of death from the view point of whether there were resulting debilitating effects and general impairment of health to an extent that would render the person materially less capable of resisting the effects of other disease or injury primarily causing death. In cases where the primary causes of death are so overwhelming that eventual death can be anticipated irrespective of coexisting conditions, there is for consideration whether there may be a reasonable basis for holding that a service-connected condition was of such severity as to have a material influence in accelerating death. It would not generally be reasonable to hold that a service-connected condition accelerated death unless such condition affected a vital organ and was of itself of a progressive or debilitating nature. 38 U.S.C.A. § 1310; 38 C.F.R. § 3.312. There are primary causes of death which by their very nature are so overwhelming that eventual death can be anticipated irrespective of coexisting conditions, but, even in such cases, there is for consideration whether there may be a reasonable basis for holding that a service-connected condition was of such severity as to have a material influence in accelerating death. In this situation, however, it would not generally be reasonable to hold that a service-connected condition accelerated death unless such condition affected a vital organ and was of itself of a progressive or debilitating nature. 38 C.F.R. § 3.312(c) (3), (4). A veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the Vietnam era (beginning in January 1962 and ending in May 1975) shall be presumed to have been exposed during such service to a herbicide agent, unless there is affirmative evidence to establish that the veteran was not exposed to any such agent during that service. 38 U.S.C.A. § 1116(a) (3); 38 C.F.R. §§ 3.307, 3.309. Effective August 31, 2010, where a Veteran was exposed to an herbicide agent during active military, naval, or air service in the Republic of Vietnam, the following diseases shall be service connected, even though there is no record of such disease during service: chloracne, or any other acneform disease consistent with chloracne; type II diabetes (also known as Type II diabetes mellitus, or adult-onset diabetes); Hodgkin's disease; ischemic heart disease, including, but not limited to, acute, subacute, and old myocardial infarction, atherosclerotic cardiovascular disease, including coronary artery disease (including coronary spasm) and coronary bypass surgery, and stable, unstable, and Prinzmetal's angina; multiple myeloma; non-Hodgkin's lymphoma; Parkinson's disease; acute and subacute peripheral neuropathy; porphyria cutanea tarda; prostate cancer; respiratory cancers (i.e., cancers of the lung, bronchus, larynx, or trachea); all chronic B-cell leukemias (including, but not limited to, hairy-cell leukemia and chronic lymphocytic leukemia); or soft tissue sarcoma (other than osteosarcoma, chondrosarcoma, Kaposi's sarcoma, or mesothelioma). 38 C.F.R. § 3.309(e) (2012). There is no positive association between exposure to herbicides and any other condition for which the Secretary has not specifically determined that a presumption of service connection is warranted. See Notice, 59 Fed. Reg. 341 -46 (1994); see also Notice, 61 Fed. Reg. 41, 442-49 (1996). A presumption of service connection based on exposure to herbicides used in the Republic of Vietnam during the Vietnam Era is not warranted for the following conditions: Cancer 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; esophageal cancer; stomach cancer; colorectal cancer (including small intestine and anus); hepatobiliary cancers (liver, gallbladder and bile ducts); pancreatic cancer; bone and joint cancer; melanoma; non-melanoma skin cancer (basal cell and squamous cell); nasopharyngeal cancer, breast cancer, cancers of reproductive organs (cervix, uterus, ovary, testes, and penis; excluding prostate); urinary bladder cancer; renal cancer; cancers of brain and nervous system (including eye); endocrine cancers (thyroid, thymus, and other endocrine; cancers at other and unspecified sites; neurobehavioral disorders (cognitive and neuropsychiatric); amyotrophic lateral sclerosis (ALS); chronic peripheral nervous system disorders; respiratory disorders; gastrointestinal immune system disorders (immune suppression, allergy, and autoimmunity); circulatory disorders (including hypertension); endometriosis; effects on thyroid homeostasis; certain reproductive effects, and, any other condition for which the Secretary has not specifically determined a presumption of service connection is warranted. See Notice, 72 Fed. Reg. 32,395 -32,407 (Jun. 12, 2007); Notice, 74 Fed. Reg. 21,258 -21260 (May 7, 2009); Notice, 75 Fed. Reg. 32540 (June 8, 2010) In order to establish service connection by presumption, based on herbicide exposure, a disease listed above (see 38 C.F.R. § 3.309(e) ) shall have become manifest to a degree of 10 percent or more at any time after service, except that chloracne or other acneform disease consistent with chloracne and porphyria cutanea tarda shall have become manifest to a degree of 10 percent or more within a year, and respiratory cancers within 30 years, after the last date on which the veteran was exposed to an herbicide agent during active military, naval, or air service. 38 C.F.R. § 3.307(a) (6) (ii). Even if the statutory presumptions are inapplicable, the United States Court of Appeals for the Federal Circuit (Federal Circuit) has held that the Veterans Dioxin and Radiation Exposure Compensation Standards Act, Pub. L. No. 98- 542, § 5, 98 Stat. 2725, 2727-29 (1984) does not preclude a veteran from establishing service connection with proof of actual direct causation. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). When all the evidence is assembled, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the appellant prevailing in either event, or whether a preponderance of the evidence is against a claim, in which case, the claim is denied. Gilbert v. Derwinski, 1 Vet. App. 49 (1990). In evaluating the claim, the Board must determine the value of all evidence submitted, including lay and medical evidence. Buchanan v. Nicholson, 451 F.3d 1331 (Fed. Cir. 2006). The evaluation of evidence generally involves a 3-step inquiry. First, the Board must determine whether the evidence comes from a "competent" source. The Board must then determine if the evidence is credible, or worthy of belief. Barr v. Nicholson, 21 Vet. App. 303 at 308 (2007) (Observing that once evidence is determined to be competent, the Board must determine whether such evidence is also credible). The third step of this inquiry requires the Board to weigh the probative value of the proffered evidence in light of the entirety of the record. Competent lay evidence means any evidence not requiring that the proponent have specialized education, training, or experience. Lay evidence is competent if it is provided by a person who has knowledge of facts or circumstances and conveys matters that can be observed and described by a lay person. 38 C.F.R. § 3.159. Lay evidence may be competent and sufficient to establish a diagnosis of a condition when: (1) a layperson is competent to identify the medical condition (i.e., when the layperson will be competent to identify the condition where the condition is simple, for example a broken leg, and sometimes not, for example, a form of cancer); (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. Jandreau v. Nicholson, 492 F. 3d 1372 (Fed. Cir. 2007); see also Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009) (where widow seeking service connection for cause of death of her husband, the Veteran, the Court holding that medical opinion not required to prove nexus between service connected mental disorder and drowning which caused Veteran's death). In ascertaining the competency of lay evidence, the Courts historically had held that a layperson is not capable of opining on matters requiring medical knowledge. Routen v. Brown, 10 Vet. App. 183 (1997). However, in certain instances, lay evidence has been found to be competent with regard to a disease with "unique and readily identifiable features" that is "capable of lay observation." See, e.g., Barr v. Nicholson, 21 Vet. App. 303 (2007) (concerning varicose veins); see also Jandreau v. Nicholson, 492 F. 3d 1372 (Fed. Cir. 2007) (a dislocated shoulder); Charles v. Principi, 16 Vet. App. 370 (2002) (tinnitus); Falzone v. Brown, 8 Vet. App. 398 (1995) (flatfeet). Laypersons have generally been found to not be competent to provide evidence in more complex medical situations. See Woehlaert v. Nicholson, 21 Vet. App. 456 (2007) (concerning rheumatic fever). The appellant contends that service connection is warranted for the cause of the Veteran's death. It is argued that the Veteran's esophageal cancer with metastases in the lungs were the result of his exposure to Agent Orange when he served in Vietnam. Initially, the Board notes that the record clearly indicates that the Veteran served in Vietnam and was thus exposed to Agent Orange. See 38 C.F.R. § 3.307(a) (6) (iii). However, esophageal cancer is not a condition enumerated among the diseases the Secretary has determined are related to herbicide (Agent Orange) exposure; rather it is expressly excluded. See 38 C.F.R. § 3.309(e). Consequently, the presumptive provisions of 38 U.S.C.A. § 1116 do not apply. Next, the Board finds that service connection for the cause of the Veteran's death is not warranted on a presumptive basis as a chronic disability. See generally 38 C.F.R. § 3.309(a). Although the Veteran's esophageal cancer is a malignant tumor, it did not manifest within a year of the Veteran's 1980 separation from service as it was not indicated prior to April 1997. See 38 C.F.R. § 3.307(a) (3). Thus, because the disease manifested more than a decade after separation, presumptive service connection is not available. 38 C.F.R. §§ 3.307(a), 3.309(a). Considering the issue of whether esophageal cancer was directly related to service, the Board finds that it was not. Indeed, the Veteran's STRs are devoid of complaints or treatment of a gastrointestinal nature. While the separation examination in October 1979 reported a pilonidal cyst, it was noted that clinical evaluation of abdomen and viscera was within normal limits. Additionally, his service treatment records reflect no complaints of, treatment for, or diagnosis of cancer of any kind; nor has the appellant so maintained. Moreover, the appellant does not argue that symptoms consistent with esophageal cancer were continuous from service and the record does not support that they were. The evidence is clear that the first medical documentation of record of an esophageal mass was in April 1997, more than 17 years after discharge. The passage of many years between discharge from active service and the medical documentation of a claimed disability is a factor to be considered. See Maxson v. West, 12 Vet. App. 453, 459 (1999), aff'd sub nom. Maxson v. Gober, 230 F.3d 1330, 1333 (Fed. Cir. 2000); see also Forshey v. Principi, 284 F.3d 1335, 1358 (Feb. Cir. 2002) (en banc) (the Board may consider in its assessment of a service connection claim the passage of a lengthy period of time wherein the veteran has not complained of the malady at issue). Moreover, the Board finds that the record does not contain competent evidence to establish a nexus, or direct link, between the underlying cause of death, esophageal cancer with pulmonary metastases, and the Veteran's period of active service. The Board notes that the claims file contains differing opinions as to whether the Veteran's cause of death is traceable to herbicide exposure in service. Where the record contains both positive and negative evidence, it is the responsibility of the Board to weigh the credibility and probative value of the medical opinions, and determine where to give credit and where to withhold the same and, in so doing, the Board may accept one medical opinion and reject others. Evans v. West, 12 Vet. App. 22, 30 (1998), citing Owens v. Brown, 7 Vet. App. 429, 433 (1995); see also Wensch v. Principi, 15 Vet. App. 362, 368 (2001) (it is not error for the Board to favor the opinion of one competent medical expert over that of another when the Board gives an adequate statement of reasons and bases for doing so). Here, the Board gives greater weight to the VA medical opinion obtained in December 2012 than it does to the private medical opinion from Dr. Dolkart submitted by the appellant in August 2010. Specifically, the Board finds that the December 2012 VA physician conducted a thorough review of the entire claims folder, including the opinion provided by Dr. Dolkart, and based his opinion on objective, documented evidence found in the claims folder. Significantly, the VA physician clearly explained the underlying reasoning for his opinions and conclusions. The VA examiner stated that it was less likely as not that the Veteran's esophageal cancer was causally related to his presumed exposure to herbicides during Vietnam service or to some other in-service event. The examiner stated that it had been established and acknowledged that the lung involvement was metastases from a primary gastrointestinal cancer and not a primary lung malignancy. The VA examiner stated that he disagreed with Dr. Dolkart's opinion because the American Cancer Society and other professional scientific organizations had extensively studied and evaluated scientific evidence regarding cancers of all types and their potential association to various toxic exposures, and there had been no link found between such exposures and any GI cancer. The Board adds that the July 2009 VA examiner similarly considered the Veteran's in-service herbicide exposure as well his service treatment records and post-service medical records in rendering his opinion. He also concluded that the Veteran's esophageal cancer was not caused by or a result of Agent Orange exposure. The July 2009 and December 2012 VA opinions appear to have been based upon a review of the record and analysis of the Veteran's entire history. See Bloom v. West, 12 Vet. App. 185, 187 (1999) [the probative value of a physician's statement is dependent, in part, upon the extent to which it reflects "clinical data or other rationale to support his opinion"]. To the contrary, the June 2007 opinion provided by Dr. Dolkart was conclusory in nature and failed to provide any underlying explanation for how the physician reached his conclusions with regard to this Veteran's case. The probative value of a medical opinion rises when it is the factually accurate, fully articulated, and sound reasoning for the conclusion (not from the mere fact that the claims file was reviewed). Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 302 (2008). In his June 2007 statement, Dr. Dolkart reported that he cared for the Veteran for many years. He also noted that the Veteran served in Vietnam and had a well-documented history of significant exposure to defoliants, including dioxin-containing agents such as Agent Orange. He noted that the Veteran ultimately died of cancer of the esophagus which he felt was likely causally related to his dioxin exposure. Dr. Dolkart provided no rationale for his conclusion, pointed to no evidence to support his opinion, and made no indication that the complete record was considered. For these reasons, the Board affords less evidentiary weight to his opinion. Similarly, the report from Dr. Gillett was based on general conclusions rather than findings pertaining to the Veteran's case. See Hayes v. Brown, 5 Vet. App. 60, 69-70 (1993) (it is the responsibility of the Board to assess the credibility and weight to be given the evidence) (citing Wood v. Derwinski, 1 Vet. App. 190, 192-93 (1992)); see also Guerrieri v. Brown, 4 Vet. App. 467, 470-471 (1993) (the probative value of medical evidence is based on the physician's knowledge and skill in analyzing the data, and the medical conclusion he reaches; as is true of any evidence, the credibility and weight to be attached to medical opinions are within the province of the Board). Moreover, reliance on the medical opinions provided in previous Board decisions also has limited probative value for the same reason. These materials do not constitute competent evidence of the medical nexus required for this specific Veteran's case. The Board has also considered the appellant's contentions that the Veteran's coronary artery disease was listed as a significant condition contributing to death. However, the VA examiner also opined that it is less likely as not that the Veteran's coronary artery disease and diabetes mellitus contributed to his death in more than a casual way. The examiner noted that he had thoroughly reviewed the Veteran's private treatment reports in the claims file from the time of his diagnosis of esophageal cancer in April 1997 to his death in March 2000. During that period, there was no indication of any worsening of either condition, nor any new cardiac events that would have caused death or hastened death. The examiner explained that the Veteran had extensive metastatic cancer to the lung with resultant respiratory failure that caused his death. The examiner stated that it was not likely that diabetes or coronary artery disease or the combination of these two contributed substantially or materially to the Veteran's death--aiding or lending assistance to the production of death. In other words, if the Veteran did not have diabetes or coronary artery disease, death would have occurred around the same time due solely to the metastatic esophageal cancer. This condition alone was severe enough to cause the Veteran's death at the time death occurred. To the extent that the appellant asserts that the Veteran's esophageal cancer with pulmonary metastases is related to his in-service herbicide exposure or that the coronary artery disease significantly contributed to the cause of his death, the Board observes that lay people are competent to testify to visible or otherwise observable symptoms of disability. See Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007); Buchanan v. Nicholson, 451 F.3d 1331, 1336 (Fed. Cir. 2006). Furthermore, lay witnesses may, in some circumstances, opine on questions of diagnosis and etiology. See Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed. Cir. 2009) (Board's categorical statement that "a valid medical opinion" was required to establish nexus, and that a layperson was "not competent" to provide testimony as to nexus because she was a layperson, conflicts with Jandreau). However, in this case, the appellant's statements that the Veteran's fatal esophageal cancer was due to his in-service herbicide exposure relate to an etiological question as to an internal, not directly observable disease, unlike testimony as to a separated shoulder, varicose veins, or flat feet, which are capable of direct observation. Compare Woehlaert with Jandreau, Barr, and Falzone, all supra. The lay statements of the appellant concerning the issue of medical nexus are therefore not competent in this regard, and the Board has placed greater probative weight on the opinions proferred by the July 2009 and December 2012 VA physicians who opined that the Veteran's esophageal cancer was not related to his in-service herbicide exposure. In conclusion, the Board finds that the competent evidence of record fails to establish that the cause of the Veteran's death was due to any incident of the Veteran's service. The preponderance of the evidence is against the claim of service connection for the cause of the Veteran's death. As there is not an approximate balance of positive and negative evidence regarding the merits of the appellant's claim that would give rise to a reasonable doubt in favor of the appellant, the benefit-of-the-doubt rule is not helpful in this instance. See 38 U.S.C.A. § 5107(b); Gilbert v. Derwinski, 1 Vet. App. 49, 54-56 (1990). For the reasons set forth above, the evidence weighs against the appellant's claim of entitlement to service connection for the cause of the Veteran's death, and the appeal must be denied. ORDER Service connection for the cause of the Veteran's death is denied. _________________________________ MARK F. HALSEY Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs