Uveal Melanoma: A Preliminary Analysis of Incidence in Irkutsk Oblast, 2023–2025, and Potential Causes of Elevated Rates Compared to Global and National Data

Abstract Objective To analyze the incidence dynamics of uveal melanoma (UM) in Irkutsk Oblast over the period 2023–2025, assess the struc­ ture of newly diagnosed cases by territory and stage, and compare the outcomes of anticancer care with those of other constituent en­ tities of the Russian Federation that lead in registered prevalence of malignant neoplasms (MN) of the eye and adnexa. Materials and Methods Data from the cancer registry of the Irkutsk Regional Oncology Dispensary (IROD) for 2023–2025 and information from the state reference book "The State of Cancer Care for the Population of Russia in 2025" (P.A. Herzen Moscow Oncology Research Institute) were used. The analysis included cases of MN of the eye and adnexa (ICD-10 code C69) of uveal localization. Incidence rates per 100,000 population, stage distri­ bution, proportion of morphological verification, mortality, and the cohort of patients under follow-up were calculated. Results Over three years, 112 new cases of UM were registered in Irkutsk Oblast (37, 36, and 39, respectively), corresponding to a crude incidence rate of approximately 1.6 per 100,000 population per year. In 2025, the region ranked 3rd in the Russian Federation for the number of newly registered patients with MN of the eye (45 individuals) and 1st for the registered prevalence rate (15.6 per 100,000). The highest proportion of stage I disease (58.3 %) and one of the lowest mortality rates (1.9 %) were observed. Conclusions Irkutsk Oblast is characterized by a consistently high incidence of UM, accompanied by a favorable stage distri­ bution and low mortality, reflecting both the biological and geo­ graphic features of the region and an adequate level of organization of ophthalmic oncology care.