Early metastatic patterns and survival in malignant melanoma

Two hundred fifty patients with distant metastasis from malignant melanoma were analyzed at the first appearance of systemic metastasis. Commonly involved sites were lung, subcutaneous tissue, brain, and liver. Frequency of liver metastasis was higher with eye and mucous membrane primary sites (P less than 0.01). Liver involvement had the worse survival compared to lung and brain. Patients with mucosal or unknown primary sites had decreased survival compared to other sites (P less than 0.01). Patients with primary melanomas thicker than 4 mm had significantly shorter survival (P less than 0.02). Single-organ involvement correlated with longer survival compared to multiple-organ involvement (P less than 0.04). Survival of metastatic disease was more favorable in patients with involvement of subcutaneous tissue only and in those with a disease-free interval of 2 years or longer. Five-year survival from first appearance of metastasis was 7% and median survival was 8 months.