Regional nodal basin control is not compromised by previous sentinel lymph node biopsy in patients with melanoma

Background: Regional nodal basin control is an important goal of lymphadenectomy in the management of melanoma patients with nodal disease. The purpose of this study was to determine if previous sentinel lymph node (SLN) biopsy compromises the ultimate regional nodal control achieved by subsequent therapeutic lymph node dissection in melanoma patients with microscopic lymph node metastases. Methods: A surgical melanoma database and hospital records were reviewed for 602 patients with primary cutaneous melanoma who underwent successful lymphatic mapping and SLN biopsy between 1991 and 1997. Results: A total of 105 (17%) of 602 patients had histologically positive SLNs and were offered therapeutic lymphadenectomy; 101 (96%) underwent this procedure. Thirty-six patients (36%) developed recurrent melanoma at one or more sites. The median follow-up period was 30 months. Recurrence in the previously dissected nodal basin was observed in 10 patients (10%); none had recurrence at only that site. Nodal basin disease appeared after local/in-transit (n = 6) or distant (n = 1) failure in seven patients and, as a component of the first site of failure, simultaneously with local/in-transit (n = 2) or distant (n = 1) recurrence in three patients. Conclusions: Nodal basin failure after lymphadenectomy in patients who underwent previous biopsy of a histologically positive SLN is primarily a function of aggressive locoregional disease rather than of contamination from previous surgery. Because regional nodal control was comparable with that in other series, we conclude that SLN biopsy with selective lymphadenectomy does not compromise regional nodal basin control.