Epidemiology of conjunctival melanocytic neoplasms

Abstract

Abstract Purpose To summarise the epidemiology of conjunctival melanocytic neoplasms. Methods Review of population‐based data on 85 patients with primary conjunctival melanoma (CM) and recently published literature. Results CM accounts for 5‐7% of ocular melanoma in Europe. Its age‐adjusted incidence has increased 2‐fold in North Europe (Finland, from 0.40 to 0.80/million) and North America (USA, from 0.27 to 0.54) during the last 25 y. In both regions, age‐adjusted incidence is higher in men. Different rates between regions result from differences in registries, ethnicity and solar radiation. Age‐adjusted incidence of CM is 3‐fold in non‐Hispanic Caucasians and 2‐fold in Hispanics relative to Asians, African Americans and American Indians; among non‐Hispanic Caucasians it increases 2.5‐fold from 48 deg. (e.g. Paris) to 21 deg. (e.g. Mecca) of latitude. CM is rare below 30 y of age (age‐specific incidence, 0.06) but increases steadily thereafter (0.48, 1.05 and 1.57 for 30‐49, 50‐70 and >70 y, respectively). Median age at diagnosis is 58‐60 y. Most CM arise in limbal (57‐64%) followed by bulbar (12‐13%), palpebral (7‐9%) and caruncular (3%) conjunctiva. Tumor‐specific 5‐and 10‐y mortality estimates are 14‐20% and 29‐38%, respectively. Non‐limbal location, increasing tumor thickness and local recurrence are consistently associated with higher mortality. Clinically detectable primary acquired melanosis (PAM) and nevus precede or accompany CM in 57‐61% and 7‐23% of patients, respectively. Median age at diagnosis of PAM is 56 y. The risk of malignant change is not precisely known and depends heavily on subtype of PAM, ranging from 10 to 90%. Conclusion Recent studies provide epidemiological data on CM which are remarkably consistent. The epidemiology of conjunctival nevi and PAM is less precisely known.