Novel Risk Factors for Uveal Melanoma in Adolescent and Young Adult Patients: A Comprehensive Case-Control Analysis.

To identify risk factors associated with uveal melanoma (UM) in adolescents and young adults (AYAs). A retrospective case-control study. Two hundred forty-seven UM patients aged 13 to 45 treated with proton beam radiation therapy and 401 age- and sex-matched controls at a tertiary academic center. We obtained demographic and genetic data, environmental exposures, and social, medical, and ocular history via retrospective chart review and phone follow-up. The main outcome measures included the prevalence and odds ratios (ORs) of the investigated risk factors in UM patients compared with controls. The median age of UM diagnosis was 38 years (range: 13-45 years); the median follow-up was 102 months (range: 3-329 months). Identified novel risk factors for UM included family history of cutaneous melanoma (OR = 3.06, P = 0.002), Ashkenazi Jewish ancestry (2.98, P = 0.02), prior eye trauma (2.94, P = 0.01), secondhand cigarette smoke exposure (2.39, P < 0.001), and previous head and neck surgery (1.81, P = 0.007). Some known risk factors identified include choroidal nevi (11.39, P < 0.001), light eye color (4.69, P < 0.001), White race (4.63, P < 0.001), outdoor sunlight exposure (4.20, P < 0.001), recent pregnancy (4.0, P = 0.002), occupational (2.39, P = 0.003) and toxic chemical (2.27, P = 0.03) exposures, family history of any cancer (2.16, P < 0.001), lack of ultraviolet-blocking eyewear use (2.13, P = 0.01), indoor tanning (2.10, P = 0.03), and propensity to sunburn (1.89, P < 0.05). The prevalence of oculodermal melanocytosis (P = 0.03) and family history of UM (P < 0.001) were significantly greater in UM patients than in controls. Uveal melanoma T-categories were as follows: 39% T1, 37% T2, 19% T3, and 5% T4. Gene expression profiling was available in 64 patients and showed 59% class 1A, 19% class 1B, and 22% class 2 tumors. Thirteen patients underwent genetic screening; identified germline mutations included CDH1, NF1, and PALB2. The estimated 10-year metastasis-free progression rate and overall survival were 80% and 81%, respectively. This study identified several novel risk factors for UM in AYAs and confirmed select established risk factors seen in UM patients of all ages. To the best of our knowledge, this is the first explicit and comprehensive investigation of risk factors among a younger cohort and may help further elucidate UM pathogenesis. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.