Prognostic factors of overall survival in patients with delayed lymph node dissection for cutaneous malignant melanoma.

To date, no study of melanoma patients who have undergone delayed lymph node dissection (DLND) has focused on the independent prognostic factors of overall survival, as calculated from surgery on the primary. Using Kaplan-Meier estimates and Cox's proportional hazard model, the significance of prognostic factors was evaluated in 173 patients who developed clinically apparent regional lymph node metastases. When calculated from excision of the primary tumour (median Breslow thickness 3.0 mm), the median survival was 38 months. When calculated from DLND, the median survival was 19 months. Multifactorial analysis revealed that the number of nodes involved at the time of DLND significantly affected both survival calculated from primary tumour excision (P = 0.0002) and survival calculated from DLND (P < 0.0001). In contrast, the well-known risk factors of primary melanoma did not significantly influence overall survival or survival after DLND. However, the remission duration between surgery on the primary and DLND clearly depended on epidermal ulceration (P = 0.001), Breslow thickness (P = 0.009) and the site of the primary melanoma (P = 0.048). Thus, in patients submitted to DLND, the risk factors of primary melanoma influence the early period of the disease, until metastatic lymph nodes become palpable. With regard to overall survival, only the extent of nodal disease determines the prognosis of these patients.