Regional Control of Melanoma Neck Node Metastasis After Selective Neck Dissection With or Without Adjuvant Radiotherapy

Abstract

To examine the effect of adjuvant radiotherapy on regional control of melanoma neck node metastasis. A single-institution retrospective study. Tertiary care cancer center. The study included 64 patients with melanoma neck node metastasis who were treated with neck dissection between 1989 and 2004 in The Netherlands Cancer Institute, Amsterdam. Twenty-four patients were treated with surgery only (15 modified radical neck dissections [MRNDs] and 9 selective neck dissections [SNDs]) (S group), and 40 patients underwent surgery (28 MRNDs and 12 SNDs) and adjuvant radiotherapy (S+RT group). Prognostic factors, ie, number of nodes, size of nodes, and extracapsular extension, were worse in the S+RT group. With a median follow-up of 2.5 years, the 2-year ipsilateral regional recurrence (RR) rate was 18% in the S+RT group and 46% in the S group. This 28% difference in RR was not statistically significant (P = .16). However, evaluation of the effect of adjuvant RT in multivariate analysis revealed a significant reduction of the RR rate after correction for the number of involved nodes (P = .04). In the S group, SND was associated with a trend toward worse RR rate compared with MRND but was not statistically significant in univariate analysis (P = .08). The type of neck dissection did not influence the RR rate in the S+RT group (P = .60). Three of the 4 RRs occurred outside the dissected volume after SND in the S group. Based on our findings, we conclude that, compared with extended neck dissection, SND leads to inferior regional control in patients with melanoma neck node metastasis who are not treated with RT, even those with low-risk neck disease. Furthermore, our results suggest that adjuvant RT improves regional control in patients with 2 or more involved nodes.