The prognostic role of the sentinel lymph node in clinically node-negative patients with cutaneous melanoma: experience of the Genoa group

Aim To define the benefit of intraoperative frozen section examination of the sentinel lymph node (sN), and to assess its prognostic value in clinically node-negative melanoma patients. Materials and methods Between July 1993 and December 2001, 214 patients with Stage I–II cutaneous melanoma underwent sN biopsy; complete follow-up data are available in 169 of 175 patients who underwent preoperative lymphoscintigraphy, lymphatic mapping with Patent Blue-V and radio-guided surgery (RGS). Results In an initial subset, the sN was identified in 35 out of 39 patients; in the principal group of 169 patients, the sN was detected in all patients. The benefit of frozen section examination, that is the proportion of all patients having intraoperative histologic examination who tested positive, was 17.2% (29/169); notably, in patients with pT1–2 vs pT3–4 melanoma the corresponding values were 2.3 and 33.3%, respectively, (P=0.000). Cox regression analysis for overall survival indicated that sN-positive patients had a two-fold increased risk of death; the most significant predictors of relapse-free survival were sN status (P=0.004), age (P=0.015), and T stage grouping (P=0.033). Conclusions The sN is a reliable predictor of regional lymph node status in patients with cutaneous melanoma. Frozen section examination can be useful in avoiding a ‘two-stage’ operative procedure in patients with tumour-positive sN, but its greatest benefit seems to be restricted to patients with pT3–pT4 primary melanoma.