Citation Nr: 1313626 Decision Date: 04/24/13 Archive Date: 05/03/13 DOCKET NO. 10-33 060 ) DATE ) ) On appeal from the Department of Veterans Affairs Regional Office in Cleveland, Ohio THE ISSUE Entitlement to service connection for adenocarcinoma of the left parotid gland, to include as secondary to herbicide exposure. REPRESENTATION Appellant represented by: Veterans of Foreign Wars of the United States ATTORNEY FOR THE BOARD A. Barone, Counsel INTRODUCTION The appellant is a Veteran who served on active duty from September 1969 to October 1974. This matter is before the Board of Veterans' Appeals (Board) on appeal from an April 2009 rating decision of the Cleveland, Ohio, Department of Veterans Affairs (VA) Regional Office (RO). The Veteran requested a hearing before the Board. Such hearing was scheduled to take place in October 2012; the Veteran failed to report for the Board hearing. In January 2013, the Board sought an advisory medical opinion from the Veterans Health Administration (VHA). The Board notes that correspondence received by the RO in December 2012 indicates that the Veteran desires to be scheduled for a new Board hearing. However, at this time the Board is now issuing a complete grant of the benefit sought on appeal. Therefore, there would be no useful purpose served by delaying this decision to further address the Veteran's hearing request and there is no prejudice to the Veteran in proceeding with the final decision at this time. FINDING OF FACT The Veteran's adenocarcinoma of the left parotid gland is reasonably shown to be related to exposure to herbicides during his service. CONCLUSION OF LAW Service connection for adenocarcinoma of the left parotid gland is warranted. 38 U.S.C.A. §§ 1101, 1110, 1116, 5107 (West 2002); 38 C.F.R. §§ 3.102, 3.303, 3.304, 3.309, 3.313 (2012). REASONS AND BASES FOR FINDING AND CONCLUSION Veterans Claims Assistance Act of 2000 (VCAA) The VCAA, in part, describes VA's duties to notify and assist claimants in substantiating a claim for VA benefits. See 38 U.S.C.A. §§ 5100, 5102, 5103, 5103A, 5106, 5107, 5126; 38 C.F.R. §§ 3.102, 3.156(a), 3.159, 3.326(a). The VCAA applies to the instant claim. However, inasmuch as the benefit sought is being granted, there is no reason to belabor the impact of the VCAA on this matter, since any error in notice or duty to assist omission is harmless. Accordingly, the Board will address the merits of the claim. Legal Criteria, Factual Background, and Analysis Service connection may be granted for disability due to disease or injury incurred in or aggravated by active military service. 38 U.S.C.A. § 1110; 38 C.F.R. § 3.303. Service connection also may be granted for any disease initially diagnosed after discharge, when all the evidence, including that pertinent to service, establishes that the disease was incurred in service. 38 C.F.R. § 3.303(d). In order to prevail on the issue of service connection, there must be medical evidence of a current disability; medical or, in certain circumstances, lay evidence of in-service incurrence or aggravation of a disease or injury; and medical evidence of a nexus between the claimed in-service disease or injury and the present disease or injury. See Hickson v. West, 12 Vet. App. 247 (1999). The determination as to whether these requirements are met is based on an analysis of all the evidence of record and an evaluation of its credibility and probative value. Baldwin v. West, 13 Vet. App. 1 (1999); 38 C.F.R. § 3.303(a). A Veteran who served in the Republic of Vietnam during the Vietnam era shall be presumed to have been exposed during such service to an 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(f). If a veteran who, during active military, naval, or air service, served in the Republic of Vietnam during the Vietnam Era (from January 9, 1962 to May 7, 1975), has one of the following diseases associated with exposure to certain herbicide agents [to include Agent Orange], then that disease shall be considered to have been incurred in or aggravated by such service, notwithstanding that there is no record of evidence of such disease during the period of such service. The diseases include AL amyloidosis; chloracne or other acneform disease consistent with chloracne; type 2 diabetes; Hodgkin's disease; ischemic heart disease; all chronic B-cell leukemias; multiple myeloma; Non-Hodgkin's lymphoma; Parkinson's disease; acute and subacute peripheral neuropathy; porphyria cutanea tarda; prostate cancer; respiratory cancers (cancer of the lung, bronchus, larynx or trachea); and soft-tissue sarcoma (other than osteosarcoma, chondrosarcoma, Kaposi's sarcoma, or mesothelioma). See 38 U.S.C.A. § 1116; 38 C.F.R. §§ 3.307(a)(6)(iii), 3.309(e), 3.313. When there is an approximate balance of positive and negative evidence regarding the merits of an issue material to the determination of the matter, the benefit of the doubt in resolving each such issue shall be given to the claimant. 38 U.S.C.A. § 5107(b); 38 C.F.R. § 3.102. When all of the evidence is assembled, VA is responsible for determining whether the evidence supports the claim or is in relative equipoise, with the veteran prevailing in either event, or whether a fair preponderance of the evidence is against the claim, in which case the claim is denied. Gilbert v. Derwinski, 1 Vet. App. 49, 55 (1990). The Board notes that it has reviewed all of the evidence in the Veteran's claims file, with an emphasis on the evidence relevant to this appeal. Although the Board has an obligation to provide reasons and bases supporting its decision, there is no need to discuss, in detail, every piece of evidence of record. Gonzales v. West, 218 F.3d 1378, 1380-81 (Fed. Cir. 2000) (VA must review the entire record, but does not have to discuss each piece of evidence). Hence, the Board will summarize the relevant evidence as appropriate and the Board's analysis will focus specifically on what the evidence shows, or fails to show, as to the claim. The Board notes that it has reviewed both the Veteran's physical claims file and "Virtual VA" (VA's electronic data storage system) to ensure that the complete record is considered. The Veteran claims that his adenocarcinoma of the left parotid gland resulted from exposure to herbicides during his service in Vietnam. The Veteran's service records document that he served in Vietnam during the Vietnam Era, and his exposure to herbicides is presumed. The Veteran's service treatment records are silent for any complaint of, treatment for, or diagnosis of adenocarcinoma. In September 2008, a lump was detected on his left temporomandibular joint, and diagnosed as a left parotid mass. In December 2008, he underwent a superficial parotidectomy to remove the mass; studies determined that the mass was a well differentiated adenocarcinoma. Following the surgery, the Veteran underwent postoperative radiation therapy. While adenocarcinoma of the parotid gland is not enumerated among the diseases determined by the Secretary to be related to herbicide exposure, and thus the presumptive provisions of 38 U.S.C.A. § 1116 do not apply, the United States Court of Appeals for the Federal Circuit (Federal Circuit) has held that a claimant is not precluded from establishing service connection for disability due to Agent Orange or pertinent herbicide agent exposure with proof of direct causation. Combee v. Brown, 34 F.3d 1039, 1042 (Fed. Cir. 1994). The Veteran has submitted internet articles which appear to associate adenocarcinoma to exposure to chemicals. In January 2013, the Board sought the medical opinion of a VHA medical expert to address the medical questions raised in this case concerning the etiology of the Veteran's adenocarcinoma. A March 2013 VHA expert medical advisory opinion thoroughly addresses this matter with discussion of relevant medical principles, reference materials (some of which were included with the report), and the pertinent facts of this case. The author of the March 2013 VHA expert medical opinion also attached pertinent reference material concerning the subject matter as well as details of the author's own substantial expertise in matters of molecular biology. The Board finds that the March 2013 VHA expert opinion is very probative evidence in this case. The March 2013 VHA expert medical opinion explains that salivary gland cancers are quite rare and details, with statistical information, the difficulty in assigning risk factors for parotid tumors in light of their relatively infrequent occurrence. The VHA expert explains that "[t]he etiology of salivary gland cancers remains undetermined." He notes that two known major risk factors are exposure to ionizing radiation "which accounts for 10-30% of these malignancies" and having had a prior cancer. Other noted risk factors include age, exposure to ultraviolet radiation, and occupational exposure to certain materials involved in "rubber manufacturing, asbestos mining, and plumbing." The expert also notes that heavy alcohol consumption and current smoking constitute risk factors in men. The VHA expert acknowledges that tactical herbicide agents (such as Agent Orange) are not among the currently established risk factors for the form of cancer at issue. However, his discussion indicates that it is nevertheless reasonable to consider Agent Orange capable of causing the Veteran's form of cancer; the VHA advisory opinion emphasizes that the extent of confirmed medical knowledge on this form of cancer remains notably limited. The March 2013 VHA expert advisory opinion explains: "In general, cancers are caused by mutations, particularly those in DNA. As Agent Orange is known to be mutagenic, then by extension, it could be responsible for mutations which cause salivary gland cancers." The expert goes on to state that "it would be difficult to establish or disprove any contribution of Agent Orange exposure to parotid gland tumors," and explains that such a determination would be difficult for reasons including the relatively small number of salivary gland cancers in the general population and the relatively high proportion of observed cases that have been attributed to ionizing radiation. The expert further explains that the etiological links between certain mutagens and specific cancers may be determined with reference to associated mutations in specific sequences of DNA linked with specific cancers, but there remains a lack of knowledge in medical science concerning the potential of mutagens to alter other key bio-genetic features (to alter specific sequences of RNA, micoRNAs, or DNA conformation, etc). The VHA expert's report acknowledges that the Veteran was a tobacco smoker until the time of his diagnosis, and notes that he was unable to find documentation relating to any synergy between tobacco use and Agent Orange. The opinion does not indicate that the history of tobacco use would make it unlikely that Agent Orange was a significant causal factor in the etiology of the left parotid gland adenocarcinoma. The VHA expert's report goes on to additionally explain that "[s]alivary gland cancers could be considered a class of head and neck cancers. Head and neck cancers have been attributed to Agent Orange." The expert reasons: "Then by extension, parotid and other salivary gland cancers could theoretically arise from mutations attributable to Agent Orange exposure." The expert acknowledges that "[a]t the present time, the American Cancer Society classifies the evidence for a relationship between Agent Orange and mouth, throat, and nose cancers (head and neck cancers) as inadequate/insufficient." The expert's acknowledgement of this information strongly suggests that it was contemplated in the key assertions presented in the advisory opinion: (1) that there is a reasonable medical basis for considering exposure to Agent Orange to be capable of causing adenocarcinoma of the left parotid gland, and (2) that there is evidence that head and neck cancers such as the Veteran's can be attributed to Agent Orange. Nothing in the VHA expert's advisory opinion suggests that the American Cancer Society's classification should be interpreted as foreclosing consideration of Agent Orange as a cause of the Veteran's adenocarcinoma of the left parotid gland. Finally, the VHA expert acknowledges that the parotid malignancy did not manifest until 2008, and asserts that this "does not negate the possibility of a relationship between Agent Orange exposure and his malignancy. There is a latency period for almost all cancers...." The VHA expert opinion suggests that it is medically reasonable to regard Agent Orange as a significant candidate for causing the adenocarcinoma of the left parotid gland. Although the expert explains that Agent Orange is not among the research-established significant risk factors for this specific cancer, the Board finds significant the expert's emphasis regarding the limitations of the state of medical research and knowledge as to the etiological profile of this particular form of cancer. Although the current state of medical research has not identified Agent Orange as a recognized potential cause of the form of cancer at issue, it appears that the VHA expert nonetheless considers Agent Orange a plausible etiological factor for the left parotid gland adenocarcinoma. The expert explains the basis for considering Agent Orange a plausible potential cause, and further explains that the established general etiological profile that omits Agent Orange is substantially limited and incomplete due to the rarity of instances of this particular form of cancer. The VHA expert appears to consider the current state of medical research on this form of cancer to be inadequately developed to compellingly discount his own impression that the mutagenic capacity of Agent Orange can cause left parotid gland adenocarcinoma. The Board finds the explanation persuasive. Acknowledging that Agent Orange is not an established risk factor for the Veteran's left parotid gland adenocarcinoma, the VHA expert explains that the mutagenic properties of Agent Orange could cause such salivary cancer; his discussion does not reflect that there is any compelling medical reason to reject Agent Orange as a potential cause for such cancer. The Board interprets the VHA expert's opinion as presenting a reasonable basis for linking the Veteran's left parotid gland adenocarcinoma to Agent Orange exposure (with additional explanation that such a link cannot more definitively be proved or disproved). The VHA expert's advisory opinion thus indicates that exposure to Agent Orange is a possible cause of the cancer at issue, and does not identify any more probable etiology for the cancer. The expert notes the Veteran's history of tobacco smoking, but does not indicate that it is a more likely etiological factor for the left parotid gland adenocarcinoma. The Board finds that the expert's opinion does not merely leave the matter to speculation; the expert explains in detail, and without contradiction, that it is reasonable to consider the mutagenic properties of Agent Orange capable of causing left parotid gland adenocarcinoma. The expert explains this in terms including principles of molecular biology. That Agent Orange has not been linked to this form of cancer by existing medical research may weigh against the Veteran's claim, but such is mitigated by the VHA expert's explanation of the limitations of current medical knowledge concerning the etiological profile of this rare cancer. The absence of an established link in current research, in this case involving a rare cancer with a poorly understood etiological profile, does not outweigh the VHA expert's explanation of the molecular-biological reasonableness of linking the claimed cancer to Agent Orange's mutagenic properties. On longitudinal review of the record, the Board finds that the evidence reasonably supports the Veteran's claim that his adenocarcinoma of the left parotid gland is causally related to his exposure to Agent Orange or other tactical herbicide agents in-service. His exposure to herbicides in Vietnam is presumed. The highly probative March 2013 VHA expert advisory opinion establishes that such exposure may reasonably be considered an etiological factor for the left parotid gland adenocarcinoma at issue. The most significant negative evidence in this case is the absence of medical research establishing Agent Orange as a recognized risk factor of this specific form of cancer. The March 2013 VHA expert advisory opinion is highly probative as to why it is medically reasonable to consider exposure to tactical herbicides a cause of the left parotid gland adenocarcinoma. The evidence in this case is certainly not unequivocal, and does not compel a conclusion that a link between military service and the Veteran's left parotid gland adenocarcinoma is firmly established. However, the Board finds that the Veteran's left parotid gland adenocarcinoma has reasonably been etiologically linked to his exposure to tactical herbicides in service, and that the probative weight of the negative evidence does not preponderate against a finding of such a link. Resolving remaining reasonable doubt in the Veteran's favor, as is required by the law (38 U.S.C.A. § 5107; 38 C.F.R. § 3.102) the Board concludes that evidence supports the Veteran's claim, and that service connection for left parotid gland adenocarcinoma is warranted. ORDER Service connection for adenocarcinoma of the left parotid gland is granted. ____________________________________________ George R. Senyk Veterans Law Judge, Board of Veterans' Appeals Department of Veterans Affairs