PREDICTING 5-YEAR OUTCOME FOR PATIENTS WITH CUTANEOUS MELANOMA IN A POPULATION-BASED STUDY

BACKGROUND, In numerous studies tumor thickness has been shown to be t he most important prognostic factor for patients with localized cutane ous melanoma. However, to our knowledge there are no population-based studies analyzing the prognosis of patients living in the United State s with cutaneous melanoma. METHODS, A prognostic model was developed w ith death as an outcome for 548 patients from Connecticut with localiz ed cutaneous melanoma Only patients with invasive melanoma who either died of the disease or were followed-up at least five years were studi ed. Fourteen pathologic parameters (histologic type of melanoma, Clark level, microscopic satellites, histologic regression, tumor thickness [Breslow], ulceration, vascular invasion, mitotic rate per mm(2), tum or-infiltrating lymphocytes, radial vs. vertical growth phase, solar e lastosis, co-existing nevus, lymphocytic response, and pigmentation) a nd three clinical variables (age, sex, and anatomic site) were analyze d using logistic regression. RESULTS. After univariate analysis, 10 pa thologic variables showed prognostic significance: histologic type (no dular and ''other'' types only), Clark level, microscopic satellites, regression (protective), tumor thickness, ulceration, vascular invasio n, mitotic rate, vertical growth phase, and solar elastosis (protectiv e). In the final model employing multivariate analysis, only tumor thi ckness and mitotic rate continued to have independent predictive value . CONCLUSIONS. In this population-based study of 548 patients in Conne cticut, tumor thickness was the most significant prognostic factor for survival of patients with localized cutaneous melanoma. Other prognos tic factors studied to date have not been conclusively verified as pro viding any additional information beyond that of tumor thickness. (C) 1996 American Cancer Society.