Citation Nr: 21041174 Decision Date: 07/08/21 Archive Date: 07/08/21 DOCKET NO. 20-14 312 DATE: July 8, 2021 ORDER Service connection for erectile dysfunction is denied. Service connection for gastrointestinal conditions of constipation, diverticulitis, colon ploys, and diverticulosis is denied. Service connection for gastroesophageal reflux disease (GERD) with acid reflux is denied. Service connection for skin cancer is denied. REMANDED The issue of service connection for headaches is remanded. FINDINGS OF FACT 1. The Veteran's erectile dysfunction was not secondary to service-connected posttraumatic stress disorder (PTSD) and was not otherwise related to an in-service injury or disease. 2. The Veteran's gastrointestinal conditions were not secondary to service-connected PTSD and were not otherwise related to an in-service injury or disease. 3. The Veteran's GERD was not secondary to service-connected PTSD and was not otherwise related to an in-service injury or disease. 4. The Veteran's skin cancer did not have its onset in service, manifest to a compensable degree within one year of discharge, or is otherwise related to active service, including as due to exposure to Agent Orange. CONCLUSIONS OF LAW 1. The criteria for service connection for erectile dysfunction are not met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 2. The criteria for service connection for gastrointestinal conditions are not met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 3. The criteria for service connection for GERD are not met. 38 U.S.C. §§ 1110, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.310. 4. The criteria for service connection for skin cancer are not met. 38 U.S.C. §§ 1110, 1112, 1113, 1137, 5107; 38 C.F.R. §§ 3.102, 3.303, 3.307, 3.309. REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran served on active duty from July 1966 to January 1970. This case is before the Board of Veterans' Appeals (Board) on appeal from April 2017 and September 2017 rating decisions from a Department of Veterans Affairs (VA) Regional Office (RO). The Veteran died in August 2020, and in September 2020, VA received a VA 21-0847 request for substitution, which VA granted in a September 2020 letter determining the appellant meets the basic eligibility for substitution as the Veteran's spouse. The Board notes the appellant's April 2020 claims for service connection for soft tissue sarcoma, gastrointestinal stromal tumor (GIST), and a groin nerve injury are still pending before the Agency of Original Jurisdiction (AOJ). The Board remanded this case for further development in August 2020 and March 2021, including new VA medical opinions and adjudication of the issue of service connection for GIST, found intertwined with the issue of service connection for headaches. A Board remand confers on the Veteran, as a matter of law, the right to compliance with the remand orders. Stegall v. West, 11 Vet. App. 268, 271 (1998). Unfortunately, although additional VA medical opinions were provided, there has not been substantial compliance with the Board's previous remand directives regarding the issue of service connection for headaches. Adjudication of the issue of service connection for GIST was not yet conducted. Another remand for the headaches claim is required. As the requested development has been completed regarding the other issues on appeal, no further action is required to comply with the remand directives regarding the other issues. Id. Service Connection Service connection will be granted for a current disability that resulted from an injury, disease, or aggravation while in active service. 38 U.S.C. § 1110; 38 C.F.R. § 3.303(a). Generally, service connection requires (1) a present disability, (2) in-service incurrence or aggravation of a disease or injury, and (3) a nexus between the present disability and the in-service incurrence or aggravation of a disease or injury. See Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Service connection may alternatively be granted on a secondary basis for a disability that is proximately due to or the result of (caused) or worsened beyond its natural progression (aggravated) by a service-connected disease or injury. Allen v. Brown, 7 Vet. App. 439, 448-49 (1995) (en banc); 38 C.F.R. § 3.310. The Veteran is competent to report symptoms and experiences he can observe. See Jandreau v. Nicholson, 492 F.3d 1372, 1377 (Fed. Cir. 2007); 38 C.F.R. § 3.159(a). VA must give due consideration to all pertinent medical and lay evidence in evaluating a claim for disability benefits. Davidson v. Shinseki, 581 F.3d 1313, 1316 (Fed Cir. 2009). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, VA shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107(b); Gilbert v. Derwinski, 1 Vet. App. 49, 57-58 (1990); 38 C.F.R. § 3.102. Because the appellant has not raised, and the record does not reasonably raise, entitlement to direct service connection for erectile dysfunction, gastrointestinal conditions, and GERD, the Board's adjudication will consider only entitlement to secondary service connection for those issues. 1. Erectile dysfunction. The appellant contends that the Veteran's erectile dysfunction was secondary to his service-connected PTSD. Alternatively, the appellant contends that a remand is required as the VA examiners' opinions were inadequate as they did not explain the specific organic etiology of the Veteran's erectile dysfunction. The preponderance of the evidence is against finding that the Veteran's erectile dysfunction was proximately due to or the result of or aggravated beyond its natural progression by his service-connected PTSD. 38 U.S.C. § 1110; 38 C.F.R. § 3.310(a). February and April 2013 private urologist treatment notes diagnosed erectile dysfunction, noting the Veteran reported a gradual and persistent pattern for the past seven years. The physician noted associated smoking but no decreased energy or hypertension and normal libido. Impotence was specified as of organic origin. The April 2015 VA examiner opined that the Veteran's erectile dysfunction was not as likely as not attributable to PTSD as the etiology of the Veteran's erectile dysfunction was vascular disease and aging. The examiner further provided the rationale that the Veteran's mental health symptoms far pre-dated the onset of erectile dysfunction in 2006. Further, the Veteran's urologist diagnosed him with erectile dysfunction of "organic origin." Additionally, the Veteran's medical records support several risk factors for organic erectile dysfunction, including tobacco history, obesity, hyperlipidemia, and evidence of vascular disease on imaging. Finally, the Veteran's erectile dysfunction exhibited a progressive trajectory before his mental health symptoms worsened. Therefore, the examiner concluded that the erectile dysfunction was less likely than not caused by the Veteran's PTSD. Additionally, it was less likely than not to be aggravated by the Veteran's PTSD. In May 2017, the appellant provided abstract summaries of three articles which respectively concluded that combat veterans with PTSD experience a significantly higher rate of sexual dysfunction than veterans without PTSD, PTSD appears to be associated with pervasive sexual dysfunction that treatment with SSRIs exacerbate, and PTSD may be a risk factor for sexual problems. A November 2020 VA examiner opined the Veteran's erectile dysfunction was less likely than not incurred in or caused by the claimed in-service injury, event, or illness or proximately due to or the result of the Veteran's PTSD. The examiner provided the rationale that a review of the medical record and service treatment records shows no evidence of the diagnosis, treatment, or symptoms suggestive of erectile dysfunction while on active duty or within one year of separation from military service. The examiner determined the Veteran's erectile dysfunction was clearly organic as organic erectile dysfunction typically develops slowly over time (except for surgery or traumatic injury), while psychogenic erectile dysfunction typically is acute and occurring in one situation but not another. The examiner further cited the National Institute on Health in noting the medical literature does not support a physiologic, biomechanical, or anatomic mechanism for the Veteran's mental health condition (PTSD) to cause or permanently aggravate erectile dysfunction beyond its natural progression. An April 2021 VA examiner further explained that the Veteran began experiencing complaints of erectile dysfunction during his late 50s. Erectile dysfunction symptoms start as early as age 40. Erectile dysfunction has a multifactorial cause but can be split into two broad categories: psychogenic and organic. Organic causes include diabetes, hypertension, atrial fibrillation, CAD, neurologic disorders, endocrinopathies, or other physical conditions. The medical community previously believed that psychologically caused erectile dysfunction was common. However, more updated literature has found that it is quite uncommon, and a more organic reason is found in the large majority of cases. The examiner cited a Medscape article on erectile dysfunction by urologist Dr. Edward David Kim. The April 2021 examiner also noted that a private urologist in 2012 determined that the cause of the Veteran's impotence was organic. The Veteran's urology treatment record clearly states that libido was not a problem, further ruling out any psychologic contribution. In addition, the Veteran's PTSD medication (bupropion) is not recognized to cause erectile dysfunction. Therefore, the examiner found that it is less likely than not that the Veteran's erectile dysfunction was aggravated beyond its natural progression by his service-connected psychiatric disability to include any medication taken to treat such disability. In June 2021, the appellant provided two medical studies to support the contention that the Veteran's erectile dysfunction was secondary to his service-connected PTSD. The study, "Erectile dysfunction in patients with anxiety disorders: a systematic review," identified a high prevalence of erectile dysfunction in the anxiety disorder population but concluded, "it is hard to say whether anxiety disorder alone is a risk factor for ED." The study, "Possible Sexual Dysfunction Associated With Bupropion for Smoking Cessation: A Case Report," was a case report on one 23-year old man who used bupropion to treat his smoking addiction, and that study noted "sexual dysfunction associated with bupropion has not been previously reported, and, as mentioned, bupropion has actually been used to treat antidepressant-induced sexual dysfunction associated with selective serotonin reuptake inhibitors. [...] It is possible that certain individuals, such as the patient described, had an atypical response to bupropion...." The most probative evidence of record demonstrates the Veteran's erectile dysfunction was organic in nature and not caused or aggravated by his service-connected PTSD. Although erectile dysfunction can be psychogenic in nature, there is no medical evidence in the record to demonstrate that the Veteran's erectile dysfunction was psychogenic in nature as three VA physicians and one private urologist all independently determined the progressive nature of the Veteran's erectile dysfunction in consideration with the age of its onset and the Veteran's comorbidities (e.g., tobacco history, obesity, hyperlipidemia, and evidence of vascular disease on imaging) which are consistent with the most common cause of erectile dysfunction: an organic onset. The combined opinions explain the Veteran's specific organic etiology (i.e., progressive nature, age of onset, and associated comorbidities). The opinions are adequate to decide on the issue of service connection as competent medical professionals made them, considered whether PTSD aggravated the organic erectile dysfunction condition, and supported their conclusions with an analysis of the Veteran's specific circumstance in a method that the Board can consider and weigh against contrary opinions. See Stefl v. Nicholson, 21 Vet. App. 120, 124 (2007); El-Amin v. Shinseki, 26 Vet. App. 136, 140 (2013). Although the appellant believes the Veteran's erectile dysfunction is proximately due to or aggravated beyond its natural progression by service-connected PTSD. The appellant, in this case, is not competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of urology and psychology. Therefore, it is outside the appellant's competence in this case because the record does not show that the appellant has the skills or medical training to make such a determination. Jandreau v. Nicholson, 492 F.3d 1372, 1377 n.4 (Fed. Cir. 2007); see also Kahana v. Shinseki, 24. Vet. App. 428 (2011). Consequently, the Board gives more probative weight to the medical opinions of the three VA examiners and one private urologist. In deciding to deny the claim, the applicability of the benefit of the doubt doctrine has been considered; however, as the preponderance of the evidence is against the claim, that doctrine is not applicable. 38 U.S.C. § 5107(b); Gilbert, 1 Vet. App. at 53-56; 38 C.F.R. § 3.102. Service connection for erectile dysfunction is denied. 2. Gastrointestinal conditions. The appellant contends that the Veteran's gastrointestinal conditions of constipation, diverticulitis, colon ploys, and diverticulosis were proximately due to his service-connected PTSD. The appellant provided medical research to support the contention that the Veteran's gastrointestinal conditions were proximately due to his service-connected PTSD. In February 2017, the appellant provided a statement from Thomas R. Insel, the former director of the National Institute of Mental Health, which states "[s]ignificant health problems are also more likely to occur in individuals with PTSD than those without the disorder, particularly hypertension, asthma, and gastrointestinal problems." In May 2017, a Fact Sheet from the National Center for PTSD was associated with the record, which states, "there is some evidence to indicate PTSD is related to cardiovascular, gastrointestinal, and musculoskeletal disorders." In June 2021, the appellant submitted a medical article abstract, "Posttraumatic Stress Disorder and Gastrointestinal Disorders in the Danish Population," which noted the study documented associations between clinician-diagnosed PTSD and all major non-malignant gastrointestinal disorders in an unselected nationwide cohort with long follow-up. The preponderance of the evidence is against finding that the Veteran's gastrointestinal conditions are due to service, including proximately due to, the result of, or aggravated beyond its natural progression by his service-connected PTSD. 38 U.S.C. § 1110; 38 C.F.R. § 3.310(a). An April 2015 VA examiner noted the Veteran's gastrointestinal conditions of diverticulitis (diagnosed in 2009), colonic polyps (diagnosed in 2006), and diverticulosis and transverse-sigmoid colon (diagnosed in 2014). The April 2015 VA examiner determined the Veteran did not have a gastrointestinal disorder that is at least as likely as not incurred in or caused by the gastrointestinal condition during service. The examiner provided the rationale that a review of the service treatment records revealed only two episodes of gastrointestinal symptoms during military service, the last being in 1969. The October 1969 separation exam did not mention a chronic gastrointestinal condition, and the Veteran has been asymptomatic since that time except for one documented episode of acute diverticulitis in 2009. Given the significant time between the symptoms in the military and the episode of diverticulitis in 2009, the events are likely unrelated. The examiner also noted that the Veteran's small colonic polyps removed during a 2006 colonoscopy were asymptomatic at the time and treated before the diverticulitis episode; thus, highly unlikely that the colonic polyps were present since military service. During a February 2018 VA primary care outpatient visit, the Veteran reported that he developed severe constipation when placed on Lexapro to treat his service-connected psychiatric disorder. A November 2020 VA examiner stated the medical literature does not support a physiologic, biomechanical, or anatomic mechanism for prescribed medications to cause or permanently aggravate gastrointestinal conditions, including constipation, diverticulitis, colon polyps, and diverticulosis beyond its natural progression. The April 2021 VA examiner noted the Veteran was diagnosed as having diverticulitis, colonic polyps, diverticulosis, and transverse-sigmoid colon during his April 2015 examination. The Veteran was reported to have acute diverticulitis in 2009, wherein a colonoscopy was done and found colonic polyps. The examiner noted the Veteran was over the age of 40 (60 years old in 2006), male, obese, and a smoker, which are the most common risk factors in developing diverticulosis and colonic polyps. Diverticulitis occurs when the diverticulosis becomes infected. Neither PTSD, depressive disorder, nor the medications used to treat these conditions are known to cause diverticulitis, colonic polyps, or diverticulosis. Therefore, the examiner opined that it was less likely than not that the Veteran's gastrointestinal conditions with constipation, including diverticulitis, colon, polyps, and diverticulosis, were proximately due to his service-connected psychiatric disability to include any medication taken to treat his service-connected psychiatric disability. The April 2015 VA examiner's opinion regarding direct service connection and the April 2021 VA examiner's opinion regarding service connection secondary to service-connected PTSD is probative. The opinions are based on an accurate medical history and provide explanations that contain clear conclusions and supporting data. Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008). The Board acknowledges and considered the research the appellant provided but notes the research was not based on the Veteran's specific medical history and finds the April 2021 examiner's opinion more probative as it considered the medical research and the Veteran's medical history in providing her medical opinion. See id. The appellant believes the Veteran's gastrointestinal conditions, including constipation, diverticulitis, colon polyps, and diverticulosis, were related to service, including proximately due to, the result of, or aggravated beyond its natural progression by the Veteran's service-connected PTSD. The appellant, in this case, is not competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the interaction between multiple organ systems in the body and pathology. Therefore, it is outside the appellant's competence in this case because the record does not show that the appellant has the medical training or credentials to make such a determination. Jandreau, 492 F.3d at 1377 n.4; see also Kahana, 24. Vet. App. 428. Consequently, the Board gives more probative weight to the opinions of the VA examiners. In deciding to deny the claim, the applicability of the benefit of the doubt doctrine has been considered; however, as the preponderance of the evidence is against the claim, that doctrine is not applicable. 38 U.S.C. § 5107(b); Gilbert, 1 Vet. App. at 53-56; 38 C.F.R. § 3.102. Service connection for the gastrointestinal conditions of constipation, diverticulitis, colon ploys, and diverticulosis is denied. 3. GERD. The appellant contends that the Veteran's GERD was secondary to his service-connected PTSD. Alternatively, the appellant argues the April 2021 VA examination was inadequate as the examiner failed to comply with the Board's March 2021 remand order. Specifically, the appellant contends the April 2021 VA examiner did not provide an etiology for the Veteran's GERD; instead, the examiner reported the generic causation of GERD without addressing the Veteran's specific GERD condition and also did not find objective evidence showing that the Veteran's lower esophageal sphincter weakened without any causation or aggravation of PTSD. Furthermore, the appellant argues the examiner's conclusion that PTSD or depression does not at all cause or aggravate GERD is a conclusory statement without any adequate explanation. The appellant argues that substantial medical literature attributes PTSD, depression, and PTSD medications to GERD, which the appellant claims establish a causal relationship. The appellant provided the abstract for "Effects of Anxiety and Depression in Patients with Gastroesophageal Reflux Disease," which concluded that in patients with GERD, increased levels of anxiety are associated with increased severity of retrosternal pain and heartburn and reduced quality of life, and that patients with GERD with hypersensitivity to gastroesophageal reflux have similar levels of anxiety and similar quality-of-life scores as other patients with GERD. The appellant also cited "PTSD, Depression, and Gastrointestinal Symptoms in Veterans of the Afghanistan and Iraq Conflicts: What's the Relation?," which concluded that Veterans with a positive PTSD or depression screen might be more likely to have GI symptoms that should be screened for by their primary care physicians, and these patients may benefit from both psychiatry and gastroenterology follow-up visits. The preponderance of the evidence is against finding that the Veteran's GERD was proximately due to, the result of, or aggravated beyond its natural progression by his service-connected PTSD. 38 U.S.C. § 1110; 38 C.F.R. § 3.310(a). During the April 2015 VA examination, the Veteran reported his acid reflux symptoms started approximately 20 years ago with burning in the chest up to the throat. The April 2015 VA examiner opined that the Veteran's acid reflux was not at least as likely as not proximately due to or the result of his PTSD with a depressive disorder. The April 2015 VA examiner provided the rationale that the Veteran's acid reflux symptoms respond well to acid suppression therapy. Further, there is some suggestion in the chart of esophageal dysmotility, and this may be contributory. Both the positive response to therapy and evidence of esophageal dysmotility argue against a psychological factor being causal. Additionally, the April 2015 VA examiner noted, in reviewing the CPRS notes addressing his mental health history, he had psychiatric symptoms since returning from Vietnam, yet stated his GERD developed only 20 years ago, or approximately 1995. Given the significant lag between the onset of mental health symptoms and GERD symptoms, it was unlikely the former caused the latter. Therefore, taken together, the medical history suggests that it was less likely than not that the GERD is secondary to PTSD. Further, the Veteran was on a stable dose of omeprazole for many years. Notes from private care providers dating back to 2008 list omeprazole 20mg daily in medication lists. The Veteran did not require an escalation of dose or addition of more agents, so the course of the GERD was stable. The physical nature of the Veteran's GERD also suggests that it was also less likely than not that PTSD has aggravated the GERD. The November 2020 VA examiner also opined that the Veteran's GERD was less likely than not proximately due to or the result of the Veteran's service-connected PTSD. The examiner noted that a review of the medical record and service treatment records showed no evidence of the diagnosis, treatment, or symptoms suggestive of GERD while on active duty or within one year of separation from military service. Any occasional indigestion or heartburn while on active duty was not consistent with GERD. The examiner explained that the evidence for the association between PTSD and gastrointestinal disorders is mixed, owing to methodologic differences across studies. Further, studies that have combined gastrointestinal disorders or symptoms for examination as one overall category may potentially obscure associations between PTSD and an individual gastrointestinal disorder diagnosis. Acid reflux (GERD) happens when the lower esophageal sphincter (LES) doesn't tighten or close properly, allowing digestive juices and other contents from the stomach to rise into the esophagus. PTSD has not been shown to have any significant effect on the LES. The Board acknowledges the appellant's argument that the April 2021 VA examiner did not provide an etiology for the Veteran's GERD; instead, the examiner reported the generic causation of GERD. However, when taken together, the VA examinations of record are adequate to decide whether the Veteran's GERD was caused or aggravated by his service-connected PTSD. The April 2015 VA examiner's explanation of the evidence of the Veteran's positive response to therapy and evidence of esophageal dysmotility taken with the April 2021 VA examiner's explanation of the physical cause of GERD is probative in demonstrating the Veteran's GERD was not caused or aggravated by psychological factors. The Board acknowledges the research provided by the appellant but does not find the research establishes a causal relationship between GERD and PTSD but instead demonstrates a correlation. Regardless, the evidence does not speak to the Veteran's GERD; indeed, the research contained no discussion of response to therapy and medication or evidence of esophageal dysmotility. The appellant believes the Veteran's GERD was proximately due to, the result of, or aggravated beyond its natural progression by PTSD. The appellant, in this case, is not competent to provide a nexus opinion regarding this issue. The issue is medically complex, as it requires knowledge of the interaction between multiple organ systems in the body and the interpretation of complicated diagnostic medical testing. Therefore, it is outside the appellant's competence in this case because the record does not show that the appellant has the skills or medical training to make such a determination. Jandreau, 492 F.3d at 1377 n.4; see also Kahana, 24. Vet. App. 428. Consequently, the Board gives more probative weight to the VA examiners' opinions. In deciding to deny the claim, the applicability of the benefit of the doubt doctrine has been considered; however, as the preponderance of the evidence is against the claim, that doctrine is not applicable. 38 U.S.C. § 5107(b); Gilbert, 1 Vet. App. at 53-56; 38 C.F.R. § 3.102. Service connection for GERD is denied. 4. Skin cancer. The appellant contends the Veteran's skin cancer was due to Agent Orange exposure; exposure is conceded. The record contains a competent diagnosis of non-melanoma skin cancer, basal cell carcinoma during the period on appeal; accordingly, evidence of a current disability during the period on appeal is found. See November 11, 2020, Medical Treatment Record Non-Government Facility. As basal cell carcinoma is not one of the diseases set forth in 38 C.F.R. § 3.309(e), a presumption based on in-service Agent Orange exposure is not warranted; however, whether there is evidence of actual direct causation of the Veteran's skin cancer due to Agent Orange exposure will be considered. See Combee v. Brown, 34 F.3d 1039, 1043-44 (Fed. Cir. 1994). Although the Veteran had skin cancer during the appeal period, and evidence shows that he was exposed to Agent Orange, the preponderance of the evidence weighs against finding that the Veteran's diagnosis of basal cell carcinoma began during service or is otherwise related to an in-service injury or disease. The appellant does not assert that the Veteran's basal cell carcinoma had onset in active service, and the available service treatment records are negative for any entries related to complaints, findings, or treatment for skin cancer or sunburns. There is no evidence that his skin cancer during the appeal period manifested within one year of separation from service. There is no factual basis for presumptive service connection for a chronic disease. 38 C.F.R. §§ 3.307(a), 3.309(a). Private treatment records show the skin cancer active during the appeal period, basal cell carcinoma on the Veteran's scalp and cheeks, was not diagnosed until October 2016, over four decades after his separation from service, and that the Veteran has a history of blistering sunburns. When taken together, the November 2020 and April 2021 VA examiners' opinions establish that the Veteran's basal cell carcinoma was not at least as likely as not related to an in-service injury or disease, including exposure to Agent Orange. The November 2020 VA examiner provided the rationale that the medical record and service treatment records show no evidence of the diagnosis, treatment, or symptoms suggestive of the current skin condition while on active duty or within one year of separation from military service. Sun exposure is the most important environmental cause of skin cancer (basal cell carcinoma, squamous cell carcinoma of the skin and malignant melanoma and actinic keratosis (BCC, SCC, MM, AK)) and most risk factors relate directly to a person's sun exposure habits or susceptibility to solar radiation. These risk factors include having fair skin, light-colored eyes, red hair, northern European ancestry, older age, childhood freckling, and an increased number of past sunburns. The type, quantity, and timing of sun exposure associated with an increased risk of BCC, SCC, MM, AK are not clearly defined. Childhood sun exposure appears to be more important than exposure during adult life. Evidence supporting this hypothesis comes from case-control studies and clinical trials. The Veteran's sun exposure while on active duty represents 0.01% of his lifetime sun exposure. The April 2021 examiner provided the rationale that basal cell carcinoma was not on the presumptive list of skin issues caused by Agent Orange exposure. Further, basal cell carcinoma is clinically acknowledged to be caused by chronic sun exposure, aging, and fair skin. Therefore, the examiner opined that the Veteran's skin cancer history was less likely than not related to the Veteran's presumed in-service Agent Orange exposure. The examiners' combined opinion is probative because it is based on an accurate medical history and provides an explanation that contains clear conclusions and supporting data that medical research does not support a finding that Agent Orange causes basal cell carcinoma. See Nieves-Rodriguez v. Peake, 22 Vet. App. 295, 304 (2008). Further, by the 2016 diagnosis of basal cell carcinoma, the Veteran had risk factors unrelated to service: being over the age of 50 and having chronic sun exposure. Although the appellant is competent to report the Veteran's formally diagnosed basal cell carcinoma, the appellant is not competent to relate basal cell carcinoma to active-duty exposure to Agent Orange. Basal cell carcinoma is medically complex, as it requires specialized medical education and the ability to interpret complicated diagnostic medical testing. Jandreau, 492 F.3d at 1377, 1377 n.4. As such, the appellant is not competent to provide an opinion as to the etiology of the Veteran's skin cancer and the appellant's statements in this regard lack weight. Consequently, without any competent evidence supporting the appellant's contention, more probative weight is given to the competent medical evidence. The preponderance of the evidence is against the issue of service connection for skin cancer. The benefit-of-the-doubt rule has been considered, but the weight of the evidence is against the claim. See Gilbert, 1 Vet. App. at 57-58; 38 C.F.R. § 3.102. The claim of service connection for skin cancer is denied. REASONS FOR REMAND Entitlement to service connection for headaches. The Board remanded the issue of service connection for headaches for once the RO decides the claim for entitlement to service connection for a GIST. The RO obtained an April 2021 VA opinion regarding whether the Veteran had a headache disability proximately due to or aggravated by the Veteran's GIST or treatment for the tumor. However, a decision on the issue of service connection for a GIST has not yet been made, and despite the negative opinion rendered in April 2021, a grant of service connection for a GIST could significantly impact a decision on the issue of headaches. A remand of the claim for service connection for headaches is required. The matters are REMANDED for the following action: After the adjudication of the claim for entitlement to service connection for a GIST has been completed, readjudicate the issue of service connection for headaches. If the benefit sought is not granted to the appellant's satisfaction, send the appellant and the representative on record a Supplemental Statement of the Case and provide an opportunity to respond. If necessary, return the case to the Board for further appellate review. R. FEINBERG Veterans Law Judge Board of Veterans' Appeals Attorney for the Board S. Costa, 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.