Citation Nr: 21062209 Decision Date: 10/06/21 Archive Date: 10/06/21 DOCKET NO. 16-22 620 DATE: October 6, 2021 ORDER Entitlement to service connection for colon cancer, to include as due to herbicide agent exposure, is denied. FINDING OF FACT Colon cancer was not manifest in service or within one year of separation and is unrelated to service, to include exposure to herbicide agents. CONCLUSION OF LAW Colon cancer was not incurred in or aggravated by service and may not be presumed to have been incurred therein. 38 U.S.C. § 1101, 1110, 1112, 1113, 1131, 1137, 1116; 38 C.F.R. §§ 3.303, 3.307, 3.309. REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran served on active duty from October 1965 to April 1985. The Veteran's service includes service in the Republic of Vietnam. This matter comes before the Board of Veterans' Appeals (Board) on appeal from an April 2015 rating decision by the Department of Veterans Affairs (VA) Regional Office (RO). This matter was previously remanded by the Board for further development in September 2019 and May 2021. The matter returns to the Board for appellate consideration. 1. Entitlement to service connection for colon cancer Veterans are entitled to compensation if they develop a 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 entitlement to service-connected compensation benefits, a Veteran 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." See Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Service connection may be granted for any disease diagnosed after discharge, when all the evidence, including that pertinent to service establishes that the disability was incurred in service. 38 C.F.R. § 3.303(d). The determination as to whether these requirements are met is based on an analysis of all the evidence of record and the evaluation of its credibility and probative value. See Baldwin v. West, 13 Vet. App. 1, 8 (1999). The Veteran's service records confirm that he served on active duty in Vietnam. His exposure to herbicide agents is thus presumed. 38 C.F.R. § 3.307(e)(6)(iii). If a veteran was exposed to an herbicide agent during active military, naval, or air service, certain diseases shall be service connected even though there is no record of such disease during service. 38 C.F.R. § 3.309(e). Colon cancer is not identified under 38 C.F.R. § 3.309(e). However, the availability of presumptive service connection for a disability based on exposure to herbicides does not preclude a Veteran from establishing service connection with proof of direct causation. Stefl v. Nicholson, 21 Vet. App. 120 (2007); see also Combee v. Brown, 34 F. 3d 1039 (Fed. Cir. 1994). The Veteran claims that his colon cancer is related to service, specifically exposure to Agent Orange. He states that the base where he was stationed at from October 1968 to October 1969, the Quang Tri Base, was exposed to Agent Orange. Service treatment records document numerous complaints and treatments. A decrease in sphincter tone was noticed in September 1977. An observation of anal discomfort and a potential fistula in November 1978 was made. A radiographic report for barium enema and fecal incontinence in December 1979, and a history of stool leakage and a "questionable" polyp around the anal region in August 1980. A report in May 1982 noted that the Veteran had diarrhea, likely due to mild gastritis. The Veteran's medical records indicate that colon cancer was first identified in 2015. A January 2015 medical record indicated that a VA examiner found a "concerning mass" in the colon. The Veteran later received a colonoscopy in February 2015, and a subsequent medical note indicates that it was identified as a "likely cancer." The mass was subsequently resected in late February 2015. The Veteran was afforded a VA examination in January 2020. When asked whether the Veteran's colon cancer was at least as likely as not related to his presumed herbicide exposure, the VA examiner concluded it was less likely than not. The VA examiner listed potential risk factors unrelated to the Veteran's service, but also noted that, according to a 2018 study about Agent Orange and Veterans "There is inadequate or insufficient evidence to determine whether there is an association between the COIs [herbicides] and any other specific type of cancer[...] Dow chemical plant workers [...] found few deaths from rectal cancer, and colon cancer was not found to be elevated in either TCP or PCP workers compared with the standardized U.S. population. Coggon et al. (2015) reported decreased, but not statistically significant risks among the UK factory workers or sprayers of phenoxy herbicides. Limited evidence is available on the biologic plausibility of an association between exposure to any of the COIs and tumors of the colon or rectum. Overall, the available evidence does not support an association between the COIs and colorectal cancers." The VA examiner submitted an addendum medical opinion in June 2021 in order to discuss incidents listed in the Veteran's service treatment records. The VA examiner stated that the veteran developed renal symptoms in 2014. As part of his evaluation an abdominal CT scan was done, which revealed a right sided colon mass. Colonoscopy confirmed the mass and biopsies revealed at least severe dysplasia. The lesion was not felt amenable to colonoscopic removal and the veteran underwent laparoscopic assisted right hemicolectomy on 2-23-2015. Pathology revealed mucinous adenocarcinoma with negative margins and nodes. No adjuvant therapy was felt needed, and available records indicate the veteran remains disease free. The VA examiner continued that "The colon cancer [was] diagnosed some 35 years after discharge was located in the proximal or ascending colon, far from the rectum. While it is known that occasionally very distal cancers (rectum, anus) can result in diarrhea and rectal leakage, cancers located in the proximal colon do not cause these symptoms. In addition, the natural history of colon cancer is such that it is very improbable that a colon cancer would 'smolder' for 3 decades before being diagnosed." Ultimately, the VA examiner reasoned that colon cancer was less likely than not related to service. The examiner listed his rationale: "the very long time between discharge and colon cancer diagnosis (30 years) is not compatible with the natural history of colon cancer [...] 2 proctosigmoidoscopic exams in 1974 and 1980 were normal, [...] a 1979 barium enema was normal, [...] a 1999 colonoscopy was normal,[...] the rectal/anus symptoms documented during active duty (fecal soilage) are not compatible with the right sided colon cancer diagnosed in 2015, and [...] a probable cause for the veteran's in-service symptoms was documented on several occasions (lax external sphincter)." In adjudicating a claim, the Board is charged with the duty to assess the credibility and weight given to evidence. See Madden v. Gober, 125 F.3d 1477, 1481 (Fed. Cir. 1997). Competency of evidence differs from weight and credibility. The former is a legal concept determining whether testimony may be heard and considered by the trier of fact, while the latter is a factual determination going to the probative value of the evidence to be made after the evidence has been admitted. Rucker v. Brown, 10 Vet. App. 67, 74 (1997). The probative value of a medical opinion primarily comes from its reasoning; threshold considerations are whether a person opining is suitably qualified and sufficiently informed. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008). In this case, the Board accepts the January 2020 and June 2021 VA medical opinions that the Veteran's colon cancer is less likely than not related to service, to include presumed herbicide exposure, as highly probative medical evidence on this point. The Board notes that the examiner rendered these opinions after thoroughly reviewing the claims file and relevant medical records. The examiner noted the Veteran's pertinent history and provided a reasoned analysis of the case. See Hernandez-Toyens v. West, 11 Vet. App. 379, 383 (1998); Gabrielson v. Brown, 7 Vet. App. 36, 40 (1994). The Board finds these medical opinions to be highly probative as they are adequately supported by additional rationale, including the citation of medical studies, as well as thorough reasoning specifically explained by the examiner. The Board has considered the lay statements of the Veteran regarding his colon cancer. The Veteran is competent to provide evidence of what he experiences, including his symptomatology and medical history. See Layno v. Brown, 6 Vet. App. 465, 469 (1994). The Veteran is competent to report what he experienced. Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007). However, the Board does not find his statements to be as probative as the VA examiner's opinion, which was based on extensive review of the record, thorough examination, consideration of the lay statements, and the VA examiner's medical expertise. Notably, the Veteran has not indicated that a medical professional provided him with a diagnosis of colon cancer during active service, or within a year of separation. In sum, the most probative evidence establishes the Veteran's colon cancer was not incurred in and are otherwise unrelated to his service, to include his exposure to herbicides during his service in Vietnam. Here, there were digestive tract complaints during service. However, he did not have characteristic manifestations sufficient to identify the chronic disease process during service or within one year of separation. Colon cancer was not noted, diagnosed or manifest during service or within one year of separation. To the extent that there is an argument of continuity, the medical evidence establishes that there was no relationship between the remote post service diagnosis and the in-service manifestations. The preponderance of the evidence is against the claim for service connection and the benefit of the doubt rule does not apply. 38 U.S.C. § 5107; Gilbert v. Derwinski, 1 Vet. App. 49, 55-56 (1990). H. N. SCHWARTZ Veterans Law Judge Board of Veterans' Appeals Attorney for the Board Jonah Nelson, Associate Counsel The Board's decision in this case is binding only with respect to the instant matter decided. This decision is not precedential and does not establish VA policies or interpretations of general applicability. 38 C.F.R. § 20.1303.