Clinicopathologic analysis of malignant melanoma in Taiwan.

BACKGROUND: Malignant melanoma is the leading cause of death among skin cancers in western countries. However, the incidence, histologic subtypes, and tumor behaviors are quite different in Asians and people of color.
OBJECTIVE: Our purpose was to define the tumor behaviors and possible prognostic predictors of melanomas based on a Taiwanese patient population.
METHODS: From the 65 patients diagnosed with melanoma at Veterans General Hospital, Taichung, we analyzed mean age at onset, gender, histologic subtypes, tumor thickness, level of invasion, primary tumor locations, and metastatic sites. Univariate analysis and multivariate analyses for survival, according to clinical and histologic tumor behaviors, were performed by means of Cox proportional hazard model. Survival curves were plotted by Kaplan-Meier method.
RESULTS: Fifty-one cutaneous melanomas were identified and analyzed by both clinical behaviors and histology. Acral lentiginous melanoma was the most common type (54.9%), followed by nodular melanoma (29.4%), superficial spreading melanoma, and lentigo maligna melanoma. Univariate analysis for overall survival of melanoma revealed that age at onset older than 55 years, male gender, ulceration of tumor, and thicker tumor have the tendency to poorer prognosis, but without significant differences. The advanced stages (III and IV) and histologic subtypes other than acral lentiginous melanoma predicted a poorer survival with significant differences. Multivariate analysis demonstrated advanced stages, and histologic subtypes were the independent risk factors for poor prognosis.
CONCLUSION: We proposed that histologic subtypes other than acral lentiginous melanoma and advanced stages have a poorer prognosis with significant differences.