Citation Nr: 18158479 Decision Date: 12/18/18 Archive Date: 12/17/18 DOCKET NO. 11-15 195A DATE: December 18, 2018 ORDER Entitlement to service connection for a cervical spine disability is denied. Entitlement to service connection for a lumbar spine disability is denied. Entitlement to service connection for a right shoulder disability is denied. Entitlement to service connection for skin cancer, including as due to herbicide exposure is denied. FINDINGS OF FACT 1. The Veteran’s cervical spine disability was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 2. The Veteran’s lumbar spine disability was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. 3. The Veteran’s right shoulder disability is not related to an in-service injury, disease, or event. 4. A skin cancer disability was not shown in service, did not manifest to a compensable degree within one year of service separation, and is not otherwise related to service. CONCLUSIONS OF LAW 1. Entitlement to service connection for a cervical spine disability is not warranted. 38 U.S.C. §§ 1101, 1110, 1112, 1113, (2012); 38 C.F.R. §§ 3.303, 3.307, 3.309 (2017). 2. Entitlement to service connection for a lumbar spine disability is not warranted. 38 U.S.C. §§ 1101, 1110, 1112, 1113, (2012); 38 C.F.R. §§ 3.303, 3.307, 3.309 (2017). 3. A right shoulder disability was not incurred in active military service. 38 U.S.C. §§ 1101, 5107 (2012); 38 C.F.R. § 3.303 (2017). 4. Skin cancer was not incurred in service, nor may it be presumed to have been incurred in service. 38 U.S.C. §§ 1101, 1110, 1112, 1113, 1116, 1131, 5103, 5103(A) (2012); 38 C.F.R. §§ 3.303, 3.307, 3.309 (2017). REASONS AND BASES FOR FINDINGS AND CONCLUSIONS The Veteran had active service from March 1963 to May 1967. This case comes to the Board of Veterans’ Appeals (Board) on appeal from February 2009 and March 2010 rating decisions by a Department of Veterans Affairs (VA) Regional Office (RO). The Veteran testified at a videoconference hearing before the undersigned Veterans’ Law Judge (VLJ) in April 2015. A transcript of the hearing is associated with the claims file. The Board previously remanded these issues in June 2015, December 2015 and September 2016 for additional development. In an April 2015 Application for Disability Compensation, the Veteran indicated he wishes to enter a claim for increased disability rating for PTSD. The Board does not have jurisdiction over this issue and it is again referred to the AOJ for appropriate action. 38 C.F.R. § 19.9 (b) (2017). Service Connection Laws and Regulations Service connection will be granted if the evidence demonstrates that a current disability resulted from an injury or disease incurred in or aggravated by active military service. 38 U.S.C. §§ 1110, 1131; 38 C.F.R. § 3.303(a). To establish a right to compensation for a present disability, 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.” Davidson v. Shinseki, 581 F.3d 1313, 1315-16 (Fed. Cir. 2009); Shedden v. Principi, 381 F.3d 1163, 1167 (Fed. Cir. 2004). Certain diseases, to include arthritis may be presumed to have been incurred in service when manifest to a compensable degree within one year of discharge from active duty. 38 U.S.C. § 1112 (2012); 38 C.F.R. §§ 3.307, 3.309 (2017). Under 38 C.F.R. § 3.303(b), an alternative method of establishing the second and third Shedden for certain chronic disabilities such as arthritis is through a demonstration of continuity of symptomatology. In relevant part, 38 U.S.C. § 1154(a) requires that the VA give “due consideration” to “all pertinent medical and lay evidence” in evaluating a claim to disability or death benefits. Lay evidence can be competent and sufficient to establish a diagnosis of a condition when (1) a layperson is competent to identify the medical condition, (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, 1377 (Fed.Cir.2007). In fact, competent medical evidence is not necessarily required when the determinative issue involves either medical etiology or a medical diagnosis. Id. at 1376-77; see also Buchanan v. Nicholson, 451 F.3d 1331, 1337 (Fed. Cir. 2006); Davidson v. Shinseki, 581 F.3d 1313 (Fed. Cir. 2009). Once evidence is determined to be competent, the Board must determine whether such evidence is also credible. See Layno, supra (distinguishing between competency (“a legal concept determining whether testimony may be heard and considered”) and credibility (“a factual determination going to the probative value of the evidence to be made after the evidence has been admitted”). When there is an approximate balance of positive and negative evidence regarding any issue material to the determination of a matter, the VA shall give the benefit of the doubt to the claimant. 38 U.S.C. § 5107(b). As addressed in the September 2016 Board remand, in November 2015 and April 2016 Written Brief Presentations, the Veteran’s representative contended the disabilities on appeal may be related to his service-connected PTSD, and that the Veteran suffers from diabetes and coronary artery disease (non-service connected). In a July 2016 statement, however, the Veteran indicated that he did not contend his claims were impacted by PTSD, and he does not suffer from nor claim diabetes and/or coronary artery disease. In addition, he expressed some frustration that these theories were being addressed. Accordingly, the Board will not pursue these matters further. 1. Cervical Spine, Lumbar Spine, Right Shoulder Factual Background The Veteran served in Vietnam from December 1965 to December 1966 with the 57th Aviation Company (Air Force Mobile FW). Service personnel records reflect that he attended Army Basic Airborne Infantry School and that his occupational specialties were as Fixed Wing Aviator, Parachutist, and Rotary Wing Aviator. His award citations reveal that he served in combat and his flight missions included insertions, extractions, and medical evacuations. The Veteran’s service treatment records demonstrate that in July 1963, the Veteran struck his right AC joint when jumping off a platform. Another July 1963 service treatment record noted an AC joint separation of the right shoulder. On his Report of Medical History for his May 1967 separation examination, the Veteran reported having recurrent back pain. It was noted that the Veteran reported low back pain while in flight school but did not have any problems recently. Post-service documents reflect that the Veteran presented with low back pain in October 1990 when he fell attempting to pick up a ladder. The diagnosis was a low back strain. A June 2004 private treatment report noted a diagnosis of a lumbar spine strain and sprain. A January 2006 MRI of the cervical spine revealed degenerative changes. However, an MRI of the lumbar spine was negative. The Veteran underwent a VA examination in February 2011. The Veteran reported that he did several in-service parachute jumps. He reported needing 5 parachute jumps to qualify and on his fourth jump he hit his neck and shoulder. The examiner noted that a July 1963 service treatment record reported that the Veteran suffered a right AC joint separation when the helmet he was wearing hit his right shoulder. The examiner also noted that in May 2006 the Veteran was diagnosed with degenerative disc disease of the cervical spine. The February 2011 VA examiner found that the Veteran’s cervical spine degenerative disc disease and resolved right shoulder AC separation and right shoulder strain were less likely than not related to the 1966 accident “or due to some other etiology,” rather, the examiner found that the cervical spine degenerative disc disease and right shoulder disabilities were “more likely consistent with age.” However, the February 2011 examiner put emphasis on an in-service plane accident in August 1966, when in fact the Veteran contends that his cervical spine, lumbar spine and right shoulder disabilities had their onset while in parachute training in 1963. The Veteran submitted treatise evidence which support his claim, that his cervical spine, lumbar spine and right shoulder disabilities are the result of in-service parachuting. Specifically, the Veteran’s representative submitted several articles in an April 2013 Written Brief Presentation which support that military parachuting may lead to lasting injury, and the Veteran submitted a statement in March 2012 citing articles to support the link between degenerative joint disease and past traumatic injury. The Veteran underwent a VA examination in October 2015. The Veteran reported having a hard landing from a parachute jump where he injured his neck while in service. He reported that after the jump his back and neck remained sore for a while. The Veteran had a diagnosis of degenerative disc disease of the lumbar spine which was first diagnosed in 2009. The Veteran also reported injuring his right shoulder when jumping from a platform. The examiner also noted that a February 2014 operative report indicated that the Veteran injured his right shoulder in June 2013. The examiner opined that it was less likely than not that the Veteran’s cervical spine, lumbar spine and right shoulder disabilities were caused by, related to, or worsened beyond natural progression by military service or parachute jumps in service. The examiner found that the Veteran’s episodic back pain that he described appeared more consistent with acute, unrelated overuse issues rather than flare ups of a chronic back issue. The examiner also noted that the Veteran’s in-service right shoulder separation had resolved while his current right shoulder supraspinatus tendon tear status post repair was not associated with his in-service right shoulder separation that took place 50 years before the June 2013 injury. The examiner also noted that while the Veteran claimed that his right shoulder disability was from parachuting in service, the service treatment records demonstrated no shoulder issues after the in-service shoulder injury. In July 2018 the Board obtained a Veterans’ Health Administration (VHA) medical opinion. The Veteran was notified about the opinion and given an opportunity to review and respond. The VHA examiner opined that it was less likely than not that the Veteran’s cervical spine, lumbar spine and right shoulder disabilities manifested in any way or had their onset during active service nor where they caused or aggravated by any aspect of service including the Veteran’s in-service right shoulder, neck, head and back injuries. The examiner additionally found that these disabilities were not related to the overall wear and tear sustained as a result of duties assigned him as an air mobile combat pilot, parachutist and infantry officer in Vietnam. The VHA examiner reported that the Veteran’s May 1967 separation examination noted recurrent back pain but was also negative for treatments or complaints of a right shoulder disability. While the Veteran had a hard fall from a parachute jump in March 1963, the examiner noted that there was no mention of back, shoulder or neck pain. In July 1963 he separated his right shoulder but when he was reexamined 20 days later it was noted that he had good range of motion, good strength and good disposition as he was to continue his airborne training that week. The VHA examiner also noted that post-service, the Veteran had annual flight physicals from the FAA from June 1968 to 2033. The examiner found that the annual FAA flight physicals established that the Veteran had no neck, back or shoulder pain from 1968 to 2003. The examiner noted that the Veteran on every annual form reported that he had no abnormalities of the spine while also noting that he had no other illness, disability or surgery on every form except for 2001 which noted appendicitis. The examiner also indicated that the Veteran attempted to relate his active duty injuries to his present cervical spine, lumbar spine and right shoulder disabilities by presenting several internet articles. The examiner noted that an article stated that spine injuries can be precipitated or aggravated by falls, slips, twisting, etc. and that injuries could manifest themselves in days, weeks, months or years. However, nowhere in the submitted literature was a 3 to 4 decade totally latent period from injury to debilitating disability for spinal pathology described. The examiner found that if the Veteran’s in-service injuries were significant enough to cause long term severe disability, it would be reasonable and plausible that he would have some symptoms of neck and back pain that he would have reported on his annual FAA flight physical examinations from 1968 to 2003. The examiner again noted that from the Veteran’s FAA statements it was obvious that the Veteran had no recurrence of his low back pain which was annotated on a May 1967 separation examination, he had no neck pain in his over 30 years of flying and he had no right shoulder complaints from 1968 to 2003 associated with his right shoulder separation. The examiner concluded that it was less likely than not that any current right shoulder, neck and back disability manifested in any way had their onset in service or were caused or aggravated by any aspect of service including the Veteran’s reported in-service right shoulder, head, neck and back injuries or overall the wear and tear sustained as a result of the Veteran’s duties as an air mobile combat pilot, parachutist and infantry officer in Vietnam. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for cervical spine, lumbar spine and right shoulder disabilities is not warranted. As there are current cervical spine, lumbar spine and right shoulder disabilities, the first element of service connection is satisfied. However, a veteran seeking disability benefits must establish not only the existence of a disability, but also an etiological connection between his military service and the disability. Boyer v. West, 210 F.3d 1351, 1353 (Fed. Cir. 2000); D’Amico v. West, 209 F.3d 1322, 1326 (Fed. Cir. 2000); Hibbard v. West, 13 Vet. App. 546, 548 (2000). Regarding the Veteran’s cervical spine and lumbar spine disabilities, as noted above, service connection may be granted on a presumptive basis for certain chronic diseases, including arthritis, if such disease is shown to be manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. See 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309 (2017). In this instance however, service connection for a cervical spine or lumbar spine disability on a presumptive basis is not warranted as the record does not show evidence of arthritis within one year of the Veteran’s separation from active duty. In this regard, the first evidence of degenerative changes of the cervical spine was in January 2006 while the first evidence of degenerative changes of the lumbar spine was in February 2011. Additionally, there is no evidence of post-service clinical treatment for cervical spine or lumbar spine disabilities for many years after his discharge from service. To the extent that the Veteran is asserting that he experienced low back and neck pain and continuing symptoms thereafter, the Board acknowledges that a layperson is competent to testify in regard to the onset and continuity of symptomatology. Heuer v. Brown, 7 Vet. App. 379, 384 (1995); Falzone v. Brown, 8 Vet. App. 398, 403 (1995); Caldwell v. Derwinski, 1 Vet. App. 466 (1991). 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) (finding that the 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, as noted specifically by the July 2018 VHA examiner, from the Veteran’s FAA statements it was obvious that the Veteran had no recurrence of his low back pain which was annotated on a May 1967 separation examination. He also had no neck pain in his over 30 years of flying and he had no right shoulder complaints from 1968 to 2003 associated with his right shoulder separation. The Board finds a history provided directly to health care providers during the course of treatment inherently more credible than statements made in support of a claim for monetary benefits. Even assuming the Veteran did experience back and neck disabilities in service, in light of his failure to reference back or neck disabilities since that time during the course of subsequent health care visits prior to 2003, the Board must find any assertion of experiencing a continuity of symptomatology since that time not credible. Accordingly, service connection for a cervical spine or lumbar spine disability on a presumptive basis is not warranted as the Veteran’s arthritis did not manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. Regarding service connection on a direct basis for the cervical spine, lumbar spine and right shoulder disabilities, the Board notes that the Veteran’s service treatment records demonstrate that in July 1963, the Veteran struck his right AC joint when jumping off a platform while another July 1963 service treatment record noted an AC joint separation of the right shoulder. Additionally, on his May 1967 separation examination, the Veteran reported having recurrent back pain. However, despite these complaints, the service treatment records were negative for any or diagnoses of any chronic neck, back or right shoulder disabilities. In particular, the record reflects that his right shoulder complaints were medically addressed in service. Additionally, the most probative opinions do not show a relationship between any current neck, back and right shoulder disabilities and the Veteran’s service. As noted above, the Veteran has submitted treatise evidence which support his claims that his neck, back and right shoulder disabilities are the result of his in-service injuries. Notably, the Veteran’s representative submitted several articles in an April 2013 Written Brief Presentation which support that military parachuting may lead to lasting injury, and the Veteran submitted a statement in March 2012 citing articles to support the link between degenerative joint disease and past traumatic injury. However, multiple VA examiners including most recently a VHA examiner in July 2018 specifically opined that it was less likely than not that the Veteran’s cervical spine, lumbar spine or right shoulder disability were caused by or the result of or incurred in service to include his documented in-service injuries. The Board finds the July 2018 to be highly probative, as it was based on a thorough review of the Veteran’s medical records, cited to relevant medical principles and specifically addressed both the Veteran’s contentions and the articles submitted by him in support of his claim. The opinion is also consistent with the other evidence of record and is supported by a detailed rationale. See Prejean v. West, 13 Vet. App. 444, 448-9 (2000) (noting that factors for assessing the probative value of a medical opinion are the physician’s access to the claims file and the thoroughness and detail of the opinion.). Notably, per the Board’s VHA request, the July 2018 VHA examiner specifically addressed whether the Veteran’s cervical spine, lumbar spine or right shoulder disabilities had their onset in service including his reported injuries and the overall wear and tear sustained of his duties assigned during his service. The VHA examiner specifically found that it was less likely than not that any current right shoulder, neck and back disability manifested in any way had their onset in service or were caused or aggravated by any aspect of service including the Veteran’s reported in-service right shoulder, head, neck and back injuries or overall the wear and tear sustained as a result of the Veteran’s duties as an air mobile combat pilot, parachutist and infantry officer in Vietnam. Additionally, while the submitted articles speak in general terms regarding the claimed disabilities and their relationship to injuries, the July 2018 VHA examiner specifically addressed the Veteran’s circumstances in relation to his cervical spine, lumbar spine and right shoulder disabilities and their potential relation to his service to include his noted in-service injuries and the cumulative effect of parachute jumping. In this regard, the Board may favor the opinion of one competent medical professional over that of another so long as an adequate statement of reasons and bases is provided. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). An evaluation of the probative value of medical opinion evidence is based on the medical expert’s personal examination of the patient, the examiner’s knowledge and skill in analyzing the data, and the medical conclusion reached. The credibility and weight to be attached to such opinions are within the province of the Board as adjudicators. Guerrieri v. Brown, 4 Vet. App. 467 (1993). Greater weight may be placed on one physician’s opinion over another depending on factors such as reasoning employed by the physicians and whether or not and the extent to which they reviewed prior clinical records and other evidence. Gabrielson v. Brown, 7 Vet. App. 36 (1994). The probative value of a medical opinion is generally based on the scope of the examination or review, as well as the relative merits of the expert’s qualifications and analytical findings, and the probative weight of a medical opinion may be reduced if the examiner fails to explain the basis for an opinion. Sklar v. Brown, 5 Vet. App. 140 (1993). As a result, the Board finds that the July 2018 opinion of the VHA examiner to be the most probative. Given that the most probative opinion is against a finding of a relationship between a cervical spine, lumbar spine and right shoulder disability and his service, the Board finds that service connection is not warranted. 2. Skin Cancer Laws and Regulations The Board observes that the Veteran served in the Republic of Vietnam. Veterans who, during active service, served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975, shall be presumed to have been exposed to an herbicide agent, unless there is affirmative evidence of non-exposure. 38 U.S.C. §§ 1116; 38 C.F.R. § 3.307. “Service in the Republic of Vietnam” includes service in the waters offshore and service in other locations if the conditions of service involved duty or visitation in the Republic of Vietnam. 38 C.F.R. §§ 3.307(a) (6) (iii), 3.313(a). If a veteran was exposed to a herbicide agent (to include Agent Orange) during active military, naval or air service and has contracted an enumerated disease to a degree of 10 percent or more at any time after service (except for chloracne and acute and subacute peripheral neuropathy which must be manifested within a year of the last exposure to an herbicide agent during service), the veteran is entitled to a presumption of service connection even though there is no record of such disease during service. 38 U.S.C. § 1116; 38 C.F.R. § 3.307, 3.309(e). The enumerated diseases are AL amyloidosis; chloracne or other acneform diseases; Type II diabetes; Non-Hodgkin’s lymphoma; Hodgkin’s disease; chronic lymphocytic leukemia; multiple myeloma; acute and subacute peripheral neuropathy; porphyria cutanea tarda; respiratory cancers; prostate cancer; and soft-tissue sarcoma (other than osteosarcoma, chondrosarcoma, Kaposi’s sarcoma, or mesothelioma). The term “soft-tissue sarcoma” includes adult fibrosarcoma, dermatofibrosarcoma protuberans, malignant fibrous histiocytoma, liposarcoma; leiomyosarcoma; epithelioid leiomyosarcoma (malignant leiomyoblastoma); rhabdomyosarcoma; ectomesenchymoma; angiosarcoma (hemangiosarcoma and lymphangiosarcoma); proliferating (systemic) angioendotheliomatosis; malignant glomus tumor; malignant hemangiopericytoma; synovial sarcoma (malignant synovioma); malignant giant cell tumor of tendon sheath; malignant schwannoma, including malignant schwannoma with rhabdomyoblastic differentiation (malignant Triton tumor), glandular and epithelioid malignant schwannomas; malignant mesenchymoma; malignant granular cell tumor; alveolar soft part sarcoma; epithelioid sarcoma; clear cell sarcoma of tendons and aponeuroses; extraskeletal Ewing’s sarcoma; congenital and infantile fibrosarcoma; malignant ganglioneuroma; and amyotrophic lateral sclerosis (ALS). 38 U.S.C. §1116; 38 C.F.R. §§ 3.307(a) (6) (iii), 3.309(e), 3.313, 3.318. Factual Background and Analysis The Veteran’s service treatment records are negative for treatments or complaints of a skin cancer disability. The Veteran underwent a VA examination in February 2011. The Veteran noted the onset of skin cancer after the onset of his service in the early 1970’s. He had a history of squamous cell carcinoma and basal cell cancer. The Veteran has submitted treatise evidence which support his claim, that his skin cancer disability is the result of exposure to herbicides in-service. Specifically, the Veteran’s representative referenced an article in an April 2013 Written Brief Presentation which supports that exposure to arsenic causes squamous cell skin cancer and keratoses, and other tumorous skin problems. The Veteran submitted a statement in January 2012 with additional treatise evidence to support a link between basal cell carcinoma and other skin conditions with dioxin as associated with Agent Orange. The Veteran underwent a VA examination in October 2015. The examiner noted diagnoses of basal cell carcinoma and squamous cell carcinoma which were diagnosed in the 1980s. The Veteran reported that as he flew missions in Vietnam, he assumed that his skin cancer resulted from Agent Orange exposure. The examiner noted that the Veteran had a fair complexion and was naturally susceptible to basal cell and squamous cell carcinomas for which the greatest risk was sun exposure. The examiner opined that it was less likely than not that the Veteran’s skin cancer disabilities were caused by, related to, or worsened beyond natural progression by military service or by herbicide exposure in service. In a February 2016 addendum opinion, the October 2015 VA examiner found that any current actinic keratoses present would be less likely than not caused by, related to, or worsened beyond the natural progression by military service to include herbicide exposure. The examiner stated sun exposure is “by far and away a greater risk than any brief exposure to arsenic or dioxin would provide.” The examiner also stated that as the Veteran spent significant time on the Gulf Coast of Alabama, has he has lived there, he most likely sustained extensive sun exposure. Per the September 2016 Board remand instructions, a VA examiner provided an addendum opinion in December 2016. The examiner opined that it was less likely than not that the Veteran’s skin conditions including basal cell carcinoma, squamous cell carcinoma and actinic keratoses were caused by or the result of or incurred in service as the service treatment records were negative for these conditions. The examiner also found that it was less likely than not that the skin conditions were caused by or a result of herbicide exposure during service as the records were silent for documentation of acute arsenic toxicity or acute dioxin toxicity and any evidence of chronic arsenic and dioxin toxicity. The examiner again found that the etiology of these skin conditions was at least as likely as not chronic sun damage. The examiner noted that actinic keratoses were common cutaneous lesions that result from the proliferation of atypical epidermal keratinocytes. Major risk factors for the development of actinic keratoses include chronic sun exposure, fair skin, advancing age and the male gender. Actinic keratoses represent early lesions on a continuum with squamous cell carcinoma. The examiner noted that chronic sun exposure was a major risk factor for the development of these lesions which accounted for the usual detection of actinic keratoses in frequently sun exposed areas. Individuals with fair skin were most likely to develop actinic keratoses. Although the majority of actinic keratoses did not progress to squamous cell carcinoma, the presence of the actinic keratoses serves as a marker of chronic sun damage and therefore, of an increased risk for the development of both squamous cell carcinoma and basal cell carcinoma. Acute high exposure to arsenic could cause severe systemic toxicity and death which was not documented in the service treatment records. Lower dose chronic arsenic exposure can result in subacute toxicity that could include skin changes and skin cancer. The records lacked documentation of such chronic exposure during military service and therefore latent, or long-term effects of arsenic exposure in the form of skin cancers were not expected. Long-term exposures to dioxins caused disruption of the nervous, immune, reproductive and endocrine system. Short-term exposure to high levels impaired the liver function and caused chloracne. Such dioxin toxicity was not documented in the service treatment records. When considering the pertinent evidence of record in light of the above-noted legal authority, the Board finds that service connection for skin cancer is not warranted. Initially, as noted above, service connection may be granted on a presumptive basis for certain chronic diseases, including skin cancer, if such disease is shown to be manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. See 38 U.S.C. §§ 1101, 1112, 1113; 38 C.F.R. §§ 3.307, 3.309 (2017). In this instance however, service connection for skin cancer on a presumptive basis is not warranted as the record does not show evidence of skin cancer within one year of the Veteran’s separation from active duty. In this regard, the first evidence of possible skin cancer is the February 2011 VA examination in which the Veteran noted the onset of skin cancer was after the onset of his service in the early 1970’s while the October 2015 VA examination noted that the skin cancer began in the 1980’s. Accordingly, service connection for skin cancer on a presumptive basis is not warranted as the Veteran’s skin cancer did not manifest to a degree of 10 percent or more within one year following the Veteran’s separation from active military service. The Board also notes that in some instances presumptive service connection is warranted based on Agent Orange exposure. In this case, exposure to herbicide agents such as Agent Orange is again conceded, as the service personnel records show that the Veteran did serve in the Republic of Vietnam. However, while the Veteran served in Vietnam, and his exposure to herbicides is therefore presumed, a skin carcinoma is not one of the conditions for which VA has specifically determined a presumption of service connection is warranted. Accordingly, entitlement to service connection on a presumptive basis based on exposure to herbicides is not warranted. The Board must also consider whether the Veteran’s skin cancer was directly caused by herbicide exposure. See Combee v. Brown, 34 F.3d 1039 (Fed. Cir. 1994). A presumption of service connection provided by law is not the sole method for showing causation in establishing a claim for service connection for disability due to herbicide exposure. See Stefl v. Nicholson, 21 Vet. App. 120 (2007). Regarding service connection on a direct basis, the Veteran’s service treatment records were negative for any complaints, treatment, or diagnoses of a skin disability and he was not diagnosed with skin cancer until many years after service. This is strong evidence against a finding of any continuity of symptomatology and weighs against his claim for service connection. See Maxson v. West, 12 Vet. App. 453 (1999), aff’d, 230 F.3d 1330 (Fed. Cir. 2000). Additionally, the most probative opinions do not show a relationship between any current skin cancer disability and the Veteran’s service. As noted above, the Veteran has submitted treatise evidence which support his claim, that his skin cancer disability is the result of exposure to herbicides in-service. Notably, the submitted articles support the idea that exposure to arsenic causes squamous cell skin cancer and keratoses, and other tumorous skin problems and that there is a link between basal cell carcinoma and other skin conditions with dioxin as associated with Agent Orange. Additionally, in an April 2016 Appellant’s Brief, the Veteran’s representative stressed that many of the Veteran’s lesions and cancers are in areas normally covered by clothing and that it would be irrational that they would be caused by sun exposure while also attaching additional articles linking skin conditions to components of herbicides. However, multiple VA examiners including most recently a VA examiner in December 2016 specifically opined that it was less likely than not that the Veteran’s skin conditions including basal cell carcinoma, squamous cell carcinoma and actinic keratoses were caused by or the result of or incurred in service to include as due to herbicide exposure. The Board finds the most recent VA examination report in December 2016 to be highly probative, as it was based on a thorough review of the Veteran’s medical records, evaluation of the Veteran, and cite to relevant medical principles. The opinion is also consistent with the other evidence of record and is supported by a detailed rationale. See Prejean v. West, 13 Vet. App. 444, 448-9 (2000) (noting that factors for assessing the probative value of a medical opinion are the physician’s access to the claims file and the thoroughness and detail of the opinion.). Notably, per the September 2016 remand instructions, the December 2016 VA examiner specifically addressed whether the Veteran had a skin cancer that was causally related to in-service herbicide exposure to include addressing the arguments presented by the Veteran and his submitted treatises. Significantly, the December 2016 VA examiner found that it was less likely than not that the skin conditions were caused by or a result of herbicide exposure during service as the records were silent for documentation of acute arsenic toxicity or acute dioxin toxicity and any evidence of chronic arsenic and dioxin toxicity. Additionally, while the submitted articles speak in general terms regarding the claimed diseases and their potential relation to herbicide exposure, the December 2016 VA examiner specifically addressed the Veteran’s circumstances in relation to his skin cancer disabilities and their potential relation to his service to include his conceded herbicide exposure. In this regard, the Board may favor the opinion of one competent medical professional over that of another so long as an adequate statement of reasons and bases is provided. See Owens v. Brown, 7 Vet. App. 429, 433 (1995). An evaluation of the probative value of medical opinion evidence is based on the medical expert’s personal examination of the patient, the examiner’s knowledge and skill in analyzing the data, and the medical conclusion reached. The credibility and weight to be attached to such opinions are within the province of the Board as adjudicators. Guerrieri v. Brown, 4 Vet. App. 467 (1993). Greater weight may be placed on one physician’s opinion over another depending on factors such as reasoning employed by the physicians and whether or not and the extent to which they reviewed prior clinical records and other evidence. Gabrielson v. Brown, 7 Vet. App. 36 (1994). The probative value of a medical opinion is generally based on the scope of the examination or review, as well as the relative merits of the expert’s qualifications and analytical findings, and the probative weight of a medical opinion may be reduced if the examiner fails to explain the basis for an opinion. Sklar v. Brown, 5 Vet. App. 140 (1993). As a result, the Board finds that the December 2016 opinion of the VA examiner to be the most probative. Consequently, entitlement to service connection for a skin cancer disability is also not warranted on a direct basis. Given that the most probative opinion is against a finding of a relationship between skin cancer and his service, to include as due to herbicide exposure, the Board finds that service connection is not warranted. 3. All Disabilities The Board notes the Veteran and his representative’s contentions regarding the etiology of his claimed cervical spine, lumbar spine, right shoulder and skin cancer disabilities. To the extent that the Veteran and his representative themselves contend that a medical relationship exists between his claimed cervical spine, lumbar spine, right shoulder and skin cancer disabilities and his service, the Board acknowledges that the Veteran is competent to testify as to his observations. Jandreau v. Nicholson, 492 F.3d 1372, 1376-77 (Fed. Cir. 2007). 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) (finding that the 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). In the instant case, however, the Board finds that cervical spine, lumbar spine, right shoulder and skin cancer disabilities are not disabilities subject to lay diagnosis as these diagnoses require medical training. More significantly, the Veteran and his representative do not have the medical expertise to provide an opinion regarding the claimed cervical spine, lumbar spine, right shoulder and skin cancer disabilities etiologies. Specifically, where the determinative issue is one of medical causation, only those with specialized medical knowledge, training, or experience are competent to provide evidence on the issue. See Jones v. West, 12 Vet. App. 460, 465 (1999). Thus, the Veteran and his representative’s assertions that there is a relationship between his claimed cervical spine, lumbar spine, right shoulder and skin cancer disabilities and his service are not sufficient in this instance and are outweighed by other probative evidence of record. Jandreau v. Nicholson, 492 F.3d 1372 (Fed. Cir. 2007). MICHAEL LANE Veterans Law Judge Board of Veterans’ Appeals ATTORNEY FOR THE BOARD James A. DeFrank, Counsel