Cutaneous Malignant Melanoma in Eastern Taiwan: Clinicopathologic Analysis of 56 Cases

Background: The incidence, histological subtypes, and tumor behaviors of cutaneous malignant melanoma are quite different in Asian and Western countries. Objectives: Our purpose was to define the epidemiology, tumor behaviors, and possible prognostic predictors of cutaneous melanomas based on an Eastern Taiwanese population. Methods: We conducted a retrospective study to collect cases of cutaneous melanoma at Buddhist Tzu-Chi General Hospital, Hualien, Taiwan, from May 1, 2003, to August 31, 2017. We analyzed mean age at onset, gender, primary tumor locations, histological subtypes, Breslow's thickness, Clark's level, ulceration, lymph nodes, and distant metastatic status. Univariate and multivariate analyses for survival were performed by means of Cox proportional hazard model. Survival curves were plotted by Kaplan-Meier method. Results: A total of 56 cases of cutaneous melanoma were recorded. The male-to-female ratio was 3.67:1. The median survival was 2.82 years (0.63-5.00 years). Acral melanoma (AM) accounts for 69.6% of cases, and feet are the most common location (62.5%). Acral lentiginous melanoma (ALM) is the most common histological type (44.6%), followed by nodular melanoma (33.9%). Poor prognostic factors include older age (>= 65 years), male gender, Breslow's thickness >4 mm, distant metastasis, and head-and-neck location. Conclusion: AM is the most common location, and ALM is the most common histological type of cutaneous melanoma in Eastern Taiwan. Melanoma in Eastern Taiwan tends to be delay diagnosed with advanced stage and thicker tumors than Western Taiwan. Prudent palm and sole examinations, improved medical accessibility, and more public educational programs may help encourage the early detection of melanoma.