RESUMO
BACKGROUND: There is some controversy in the literature regarding the possible prognostic value of cases of multiple lymphatic basin drainage (MLBD). The purpose of this work was to study the differences in prognosis depending on whether there is MLBD from primary cutaneous melanoma. METHODS: We conducted a cohort analysis from a prospective database, and 112 consecutive patients with cutaneous melanoma were included. Sentinel lymph node biopsy (SLNB) was done in all of them. MLBD was defined as the occurrence of two or more different nodal basins from the same lesion. The demographic and clinical data for cases with a single nodal drainage basin and MLBD were statistically compared using Fisher's exact test, the χ(2) test, or Mann-Whitney's test according to the type of variables studied. Multivariate analysis also was performed on the disease-free survival rate using logistic regression analysis. The distribution of disease-free survival was determined using a Cox proportional risk model. RESULTS: Only gender (27% men and 8% women; P = 0.01) and the localization of the primary tumor in the trunk (P < 0.001) were associated with the presence of MLBD. It also was observed that the cases with a high Breslow thickness or with MLBD were only associated with a worse disease-free survival rate in cases with positive (P < 0.01 and P = 0.047, respectively) and negative (P < 0.011 and P = 0.019, respectively) SLNB. CONCLUSIONS: This study suggests that both Breslow thickness and the presence of MLBD are statistically significant independent prognostic factors of disease-free survival in patients with cutaneous melanoma.