Background. Sentinel node (SN) biopsy (SNB) is not routinely performed for melanoma patients with local recurrence (LR) or in-transit metastasis (ITM). This study aimed to describe the technique, findings, and prognostic value of this procedure, and the outcome for such patients at our institution.
Methods. Prospectively collected data were obtained from the Melanoma Institute Australia database. Patients who had SNB for LR or ITM between 1992 and 2015 were included in the study. Patient and primary tumor characteristics, lymphoscintigrams, SNB results, and follow-up data were analyzed.
Results. Overall, 7999 patients underwent SNB, 128 (1.6%) of whom met the selection criteria. The SNB procedure was performed for 85 of 1516 patients with LR (6%), 17 of 1671 patients with ITM from a known primary tumor (1%), and 26 of 170 patients who presented with ITM from an unknown primary site (15%). The SN identification rate was 100%. Metastatic melanoma was identified in an SN from 16 of the 128 patients (13%). Follow-up data were available for 114 patients. The false-negative rate was 27%. The SN-positive patients had significantly worse overall survival than the SN-negative patients, with respective 5-year survival rates of 54% and 81% (P = 0.01).
Conclusion. The SNB procedure was performed infrequently for LR or ITM. The SNs were positive for 13% of the patients with LR or ITM. Positive SNs were associated with worse overall survival. Despite the false-negative rate of 27%, the procedure yielded information that was relevant for staging and prognosis. The SNB procedure should be considered for patients with LR or ITM.