Factors that predict the presence of sentinel lymph node metastasis in patients with melanoma

Background. This analysis was performed to identify prognostic factors that are predictive of sentinel lymph node (SLN) metastasis in melanoma. Methods. Analysis was performed of a multi-institutional, prospective, rand omized trial of SLN biopsy for melanoma. Eligibility criteria included age 18 to 70 years, Breslow thickness of 1.0 mm or more, and clinically negativ e regional lymph nodes. SLNs were evaluated by serial sectioning and immuno histochemistry for S100. Univariate chi-square and multivariate logistic re gression analyses were preformed to assess factors predictive of the presen ce of a positive SLN. Probability values of less than .05 were considered s ignificant. Results. SLNs were identified in 99.7% of patients. A total of 1058 patient s were evaluated, 961 patients had complete data and were included in the s tatistical analysis. SLNs were positive for tumor in 208 of 961 patients (2 2%). Breslow thickness, Clark level, ulceration, and patient age were facto rs that were found to be independently predictive of the presence of SLN me tastasis. Conclusions. Increasing Breslow thickness, Clark level of more than III, th e presence of ulceration, and patient age of 60 years or less are the most important independent prognostic factors associated with the finding of pos itive SLN in patients with melanoma.