Melanoma is a highly malignant cancer responsible for 55 000 deaths worldwide annually. Despite its severity, its epidemiology in Japan remains understudied owing to its rarity among Asians. This study aimed to determine the incidence of melanoma in Japan using data from the National Cancer Registry.

We analyzed data from patients diagnosed with melanoma in 2016 and 2017, classifying cases according to subtype using the World Health Organization (WHO) and other tumor classifications. Tumor incidence was calculated as the number of new cases divided by the corresponding population per year.

A total of 6176 patients were included in the study. The subtypes were distributed as follows: cutaneous (76.2%), mucosal (19.6%), uveal (2.7%), and neural organ/unknown primary melanoma (1.3%). The overall age-adjusted incidence of melanoma was 2.57 per 100 000 persons in the Japanese and 1.15 per 100 000 persons in the WHO population models.

This study provided comprehensive epidemiological data on melanoma in Japan using population-based registry data, highlighting the relatively low incidence of melanoma compared with that worldwide and emphasizing the need for further research into its unique epidemiology in Asian populations.