Effect of anatomical location on prognosis in patients with clinical stage I melanoma.

A study of the influence of the anatomical location of malignant melanoma on the prognosis of 971 patients with stage I disease disclosed specific high-, intermediate-, and low-risk sites. High-risk sites included scalp, mandibular area, midline of trunk (anterior and posterior), upper medial thighs, hands, feet (except the arches), popliteal fossae, and genitalia. The life-table-adjusted five-year disease-free survival was 54% in the high-risk locations, 79% in intermediate-risk locations, and 93% in low-risk sites. A Cox proportional hazards analysis demonstrated that the grouping of lesions by their anatomical risk location had prognostic value that was significant in a model of eight other known predictive variables (thickness, sex, age, type, level, mitotic index, ulceration, and presence of preexistent nevus). The results indicate that anatomical location of the primary melanoma is significantly associated with five-year disease-free survival.