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.

Histological characteristics of metastasizing thin melanomas: a case-control study of 43 cases.

OBJECTIVE: To study clinical and histological features associated with metastasizing thin melanomas (MTMs). DESIGN: Case-control study of clinicopathological features of patients with MTMs by a panel of 10 dermatopathologists. SETTING: Members of the North American Melanoma Pathology Study Group selected the cases from the melanoma databases at 8 academic institutions. PATIENTS: Forty-three patients with MTMs (<1 mm thick) and 42 control subjects without metastasis matched for age, sex, tumor site, and Breslow thickness. INTERVENTION: None. MAIN OUTCOME MEASURES: Clinical (age, sex, site of lesion, stage at diagnosis, metastasis site, disease-free survival, and outcome) and histological (Breslow thickness, Clark level, growth phase, regression, and inflammatory response) features of patients with MTMs vs controls. RESULTS: There was an overrepresentation of axial tumors among patients with MTMs. Extensive regression was present in 18 patients (42%) with MTM vs 2 matched control subjects (5%) (95% confidence interval, 21%-53%; P =.001). Other histological variables were not significantly different. Two patients had melanomas in situ with subsequent metastasis. CONCLUSIONS: Thin melanomas with extensive regression represent a group at higher risk for the development of metastasis. Furthermore, the risk of metastasis cannot be dismissed in cases of melanoma in situ.