Sentinel lymph node status in melanoma: prognostic value in a tertiary hospital and correlation with mitotic activity.

BACKGROUND The prognostic value of sentinel lymph node (SLN) biopsy findings and mitotic activity in melanoma has been confirmed in the literature, but the relation between them has not been well established. OBJECTIVES The main objective was to describe and analyze the correlation between SLN biopsy results and the mitotic rate in patients treated for melanoma in our hospital. METHODS A total of 139 consecutive patients who underwent SLN biopsy between May 2001 and May 2009 were included. The relation between the mitotic rate and SLN status was analyzed with the χ(2) test and the Fischer exact test. RESULTS The correlation between the 2 variables was nonsignificant (P =.071) in the patient series overall, but a significant association was found in the subgroup of patients with tumors of Breslow thickness between 1 and 4mm (P =.034). The likelihood (odds ratio) of SLN positivity with a mitotic rate of less than 1 mitosis/mm2 in this subgroup was 0.838 (95% CI, 0.758-0.926). CONCLUSIONS Our findings support use of the mitotic rate to predict SLN status in melanoma tumors of intermediate thickness. Our study also shows the need for further investigation of the relation between these 2 variables in thin and thick tumors.