Lessons learned from the Sunbelt Melanoma Trial

The Sunbelt Melanoma Trial is an ongoing multicenter prospective randomized trial that involves 79 centers and over 3600 patients from across the United States and Canada. This is one of the first large randomized studies to incorporate molecular staging using reverse transcriptase polymerase chain reaction (RT-PCR). While the results related to the primary endpoints of the study are not yet available, several analyses have shed light on many aspects of sentinel lymph node (SLN) biopsy and melanoma prognostic factors. In particular, we have developed a practical definition of sentinel nodes based on the degree of radioactivity. We have established the low rate of postoperative complications associated with SLN biopsy as compared to complete lymph node dissection. We have identified factors that predict the presence of SLN metastases. In contrast, we have been unable to identify factors that indicate a low risk of non-sentinel node metastases in patients with a positive sentinel node, suggesting that completion lymphadenectomy is appropriate for such patients. We have further established the value of identifying interval or in-transit sentinel nodes, which can be the only site of nodal metastasis. We have evaluated the particular challenges associated with SLN biopsy of head and neck melanomas, have evaluated the patterns of early recurrence, and have identified an interesting correlation between increasing patient age and a number of prognostic factors. Future analyses will evaluate the benefit of early therapeutic lymphadenectomy and early institution of adjuvant interferon alfa-2b therapy, as well as the validity of molecular staging.