Citation Nr: 18150369 Decision Date: 11/15/18 Archive Date: 11/15/18 DOCKET NO. 14-35 368A DATE: November 15, 2018 ORDER Entitlement to service connection for colorectal cancer is granted. FINDING OF FACT The evidence is in relative equipoise as to whether the Veteran’s currently diagnosed colorectal cancer residuals are related to service. CONCLUSION OF LAW The criteria for establishing entitlement to service connection for colorectal cancer have been met. 38 U.S.C. §§ 1110, 1131, 5103(a), 5107 (2012); 38 C.F.R. §§ 3.102, 3.303 (2017). REASONS AND BASES FOR FINDING AND CONCLUSION The Veteran served on active duty from September 1974 to September 1997. This matter comes before the Board of Veterans’ Appeals (Board) on appeal from a June 2014 rating decision of the Department of Veterans Affairs (VA) Regional Office (RO) in St. Petersburg, Florida, which denied entitlement to service connection for colorectal cancer. The Veteran timely perfected an appeal to the June 2014 rating decision. See July 2014 Notice of Disagreement; October 2014 Statement of the Case; October 2014 VA Form 9. The Veteran originally requested a Board hearing in his October 2014 Substantive Appeal. However, in a July 2018 signed correspondence, the Veteran, through his representative, requested that his hearing request be withdrawn. The Veteran has not requested an additional hearing. As such, the Board considers his hearing request withdrawn. 38 C.F.R. § 20.704 (2017). Service Connection for Colorectal Cancer The Veteran contends that his colorectal cancer is due to long-term exposure to various chemicals, including those found in synthetic lubricants and petrochemicals, jet fuel, aviation fuel, and cleaning compounds, during his twenty-three years serving as a jet engine mechanic in the Air Force. See July 2014 Notice of Disagreement. Service connection is warranted where the evidence of record establishes that a particular injury or disease resulting in disability was incurred in the line of duty in the active military service or, if pre-existing such service, was aggravated thereby. 38 U.S.C. 1110, 1131; 38 C.F.R. 3.303 (a). Establishing service connection generally requires (1) evidence of a current disability; (2) evidence of in-service incurrence or aggravation of a disease or injury; and (3) evidence of a nexus between the claimed in-service disease or injury and the present disability. Shedden v. Principi, 381 F. 3d 1163, 1167 (Fed. Cir. 2004); see also Caluza v. Brown, 7 Vet. App. 498, 506 (1995), aff’d per curiam, 78 F. 3d 604 (Fed. Cir. 1996) (table); 38 C.F.R. § 3.303. Service connection may also be granted for any disease diagnosed after the military discharge, when all the evidence, including that pertinent to the period of military service, establishes that the disease was incurred during the active military service. 38 U.S.C. § 1113 (b); 38 C.F.R. § 3.303 (d). In determining whether service connection is warranted for a disability, 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 preponderance of the evidence is against the claim, in which case the claim is denied. 38 U.S.C. § 5107; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination, the benefit of the doubt is afforded to the Veteran. In the present case, private and VA treatment records reflect that the Veteran was diagnosed with colon cancer in 2008, with recurrence of metastatic colorectal cancer in 2010, 2013, and 2016. Thus, the Veteran has satisfied the first Shedden requirement of a current disability. Additionally, although service treatment records document no complaints, findings, or diagnosis of, or evidence of treatment for, colorectal cancer during service, personnel records show that the Veteran served as a tactical aircraft superintendent in the Air Force for twenty-three years, and he provided competent, credible evidence indicating that he was frequently exposed to petroleum products and other chemicals, including diesel fuel, jet fuel, and gasoline, during his active service. Specifically, in a July 2014 statement, the Veteran reported that over a twenty-three-year period as a jet aircraft maintenance mechanic, he was regularly exposed to synthetic lubricants and petro chemicals, jet fuel, turbine engine exhaust fumes, greases, paint strippers, and cleaning compounds like acetone and carbon. He also indicated that he was exposed to airborne hydrazine on three occasions after the inadvertent firing of an F-16 aircraft’s EPU. The Veteran further reported that he served on an aircraft crash response team from 1989 to 1997, where he was exposed to broken and damaged carbon fiber structural components and jet fuel as he traversed crash sites to recover crashed aircraft. The Veteran is competent to report his in-service experiences, and the Board finds that the Veteran’s reports regarding frequent exposure to petroleum products and other chemicals to be consistent with the circumstances and conditions of his service as an aircraft mechanic. See 38 U.S.C. § 1154. Thus, the second element of service connection is met. See Shedden, 381 F.3d at 1166-67. The question then becomes whether a nexus, or relationship, between the claimed in-service injury and the current disability has been shown. The claims folder contains competing medical opinions that address this question. In October 2014, a VA physician, who reviewed the claims file, opined that the Veteran’s metastatic colon cancer was less likely than not caused by his exposure to hazardous materials during military service. The examiner noted that genetic factors, environmental exposures, and inflammatory conditions of the digestive tract are all involved in the development of colorectal cancer, with current research indicating that genetic factors have the greatest correlation to colorectal cancer. The examiner also indicated that obesity and lifestyle choices, such as cigarette smoking, alcohol consumption, and sedentary habits, have also been associated with increased risk for colorectal cancer. The examiner further noted that age is also a major risk factor for sporadic colorectal cancer. The examiner indicated that the Veteran’s maternal grandmother and maternal aunt had colon cancer and that the Veteran was about 56 years old when his metastatic colon cancer was discovered. Thus, the examiner concluded that “while the [V]eteran had exposure to various agents while on active duty, the [V]eteran’s age and genetic factors would be more likely responsible in this [V]eteran’s case to have resulted in the development of his colon cancer.” In a September 2018 report, a private oncologist, who reviewed the claims file, opined that the Veteran’s colon cancer was more likely than not caused by his exposure to hazardous chemicals while serving as an aircraft mechanic in the Air Force. The private oncologist indicated that, as an aircraft mechanic, the Veteran was exposed to at least four recognized human carcinogens, including benzene, diesel, Trichloroethylene (TCE), and asbestos. The private oncologist further noted that diesel and asbestos are each recognized as potentially causative in the development of colon cancer. Regarding the Veteran’s age at diagnosis, the oncologist noted that the Veteran was first diagnosed with colon cancer at age 54, which is 15 years younger than the average age for colon cancer. The private oncologist acknowledged that family history is also a risk factor for colon cancer; however, the oncologist also noted that the Veteran’s relatives with colon cancer were second-degree, rather than first-degree, relatives, which makes genetics a “significantly lesser risk factor” in the development of the Veteran’s colon cancer. The oncologist also indicated that 80 percent of colon cancers occur without a known family history, which implies “that they are more likely than not the result of exposure to environmental factors.” The oncologist also noted that the Veteran has none of the other risk factors for the development of colon cancer in that he is not African American, a confirmed never-smoker, not diabetic, and has no history of inflammatory bowel disease. The oncologist concluded “based upon a reasonable degree of medical certainty and scientific probability, that is it more likely than not (a greater than 50% chance) that [the Veteran’s] colon cancer was caused by his exposure to recognized human carcinogens, specifically Diesel and Asbestos, during his 23 years as an aircraft mechanic while service in the US Air Force.” The Board finds that the opinions of record are probative as both the VA and private examiners reviewed the claims file, discussed the medical literature in relation to the Veteran’s specific risk factors, and supported their opinions with adequate rationale. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 301 (2008). The Board finds no adequate reason to favor the negative opinion over the positive opinion that is favorable to the Veteran’s claim. Madden v. Gober, 125 F.3d 1477, 1481 (Fed. Cir. 1997) (in evaluating the evidence and rendering a decision on the merits, the Board is required to assess the credibility and probative value of proffered evidence in the context of the record as a whole); Evans v. West, 12 Vet. App. 22, 26 (1998). Accordingly, the Board finds that the positive and the negative opinions put the evidence in relative equipoise as to whether the Veteran’s currently diagnosed colorectal cancer is related to the Veteran’s in-service exposures. As the reasonable doubt created by this relative equipoise in the evidence must be resolved in favor of the Veteran, the Board finds that entitlement to service connection for colorectal cancer is warranted. 38 U.S.C. § 5107(b); 38 C.F.R. § 3.102; Gilbert v. Derwinski, 1 Vet. App. 49 (1990). DEBORAH W. SINGLETON Veterans Law Judge Board of Veterans’ Appeals ATTORNEY FOR THE BOARD R. Kipper, Associate Counsel