Sentinel lymph node biopsy is prognostic but not therapeutic for thick melanoma.

Background: Sentinel lymph node biopsy (SNB) as a staging and therapeutic procedure in melanomas 1-4 mm in thickness has been investigated extensively, however, the clinical value of SNB in thick melanomas is poorly understood.

Methods: Patients undergoing operation for clinically node-negative melanoma >4 mm in depth between 2003 and 2010 were identified in the Surveillance Epidemiology and End Results registry. Two groups were constructed: one with a wide excision with SNB and the other with wide excision alone.