Clinical node-negative thick melanoma.

Background: Patients with T4 N0 M0 melanoma are considered at high risk for having occult metastases, and adjuvant therapy is usually recommended.
Hypothesis: Long-term survival in patients with thick melanoma is not universally poor.
Design: A retrospective study.
Setting: University teaching hospital.
Patients: We evaluated clinical node-negative thick (> or = l4.0 mm) melanoma in 151 patients who received their primary definitive surgical treatment in our department. None of these patients received any adjuvant therapy.
Results: Median follow-up was 44 months; median thickness, 5.5 mm. Median overall (OS) and disease-free survivals (DFS) were 70 (5-year survival, 52%) and 51 months (5-year survival, 47%), respectively. Patients with node-positive disease faired significantly worse than did those with node-negative disease. Median OS and DFS for patients with node-positive disease were 49 and 32 months (5-year survival, 35%), respectively, compared with 209 (5-year survival, 61%) and 165 months (5-year survival, 56%), respectively, for patients with node-negative disease. Similarly, OS and DFS were significantly lower when the primary tumor had at least 5 mitoses/mm(2) or was located in the head and neck region. After multivariate analysis, status of the lymph nodes was the most predictive variable for OS and DFS.
Conclusions: The thickness of melanoma, by itself, should not be used as a criterion for adjuvant therapy. Other prognostic factors should be considered.