Risk of New Primary Cancer in Patients with Posterior Uveal Melanoma: A National Cohort Study

SIMPLE SUMMARY: Prior studies on the risk of new primary cancer among patients with posterior uveal melanoma have produced conflicting results, and the role of other risk factors relevant to cancer formation, such as socioeconomic status, has not been investigated. The focus on the genetic susceptibility of cancer among patients with uveal melanoma has increased with the recognition of BRCA1-Associated Protein 1 (BAP1) tumor predisposition syndrome presenting with an increased incidence of uveal melanoma, renal cell carcinoma, mesothelioma, and cutaneous melanoma in the affected family members. Our study evaluates the risk of new primary cancer in a validated almost complete national cohort of clinically and histopathologically well described posterior uveal melanomas from 1968 through 2016. Our study showed a 21% increased incidence of new primary cancer following the diagnosis of posterior uveal melanoma. The risk was independent of socioeconomic factors and was not restricted to specific cancer types. ABSTRACT: Background: Studies on the risk of new primary cancer in patients with posterior uveal melanoma (UM) have produced conflicting results, and the role of socioeconomic status (SES) is unknown. The purpose of this population-based matched cohort study was to determine the risk of new primary cancer following the diagnosis of posterior UM. Methods: 2179 patients with posterior UM 1968–2016 and 22,717 matched controls without cancer were included. Incidence and time-dependent hazard ratio (HR) of new primary cancer were described, and the effect of SES was emphasized in a sub-cohort. Results: The incidence of new primary cancer was increased in patients with posterior UM, rate ratio (RR) 1.21 (95% CI: 1.08; 1.35), but the specific cancer types did not differ compared to the controls. The rate of new primary cancer following the diagnosis of posterior UM was significantly increased 2–5 years (HR 1.49 (95% CI: 1.23; 1.80)) and 11–15 years (HR: 1.49 (95% CI: 1.12; 1.99)), and adjusting for SES did not change the rate (HR 1.35 (95% CI:1.20; 1.55)). Conclusions: Patients with posterior UM have an increased risk of new primary cancer independent of SES. No difference in incidence of specific cancer type was observed compared to the control group.