Metastasis of melanoma in non-sentinel nodes in patients with metastatic sentinel node. Can we avoid complementary lymphadenectomy?

Background: Lymph mapping with sentinel node biopsy is the standard procedure for lymph node staging in patients with cutaneous melanoma with a tumor thickness of 1 mm or greater. Patients who have metastases in sentinel node must undergo complementary lymphadenectomy; however, it has not been shown to improve survival.

Objective: To know the prevalence in our setting of metastases in the product of complementary lymphadenectomy in patients with metastatic sentinel node.

Method: Evaluation of a descriptive, retrospective, observational and analytical cohort of patients with metastatic sentinel node submitted to lymphadenectomy. Multivariate analysis of tumor thickness, neural invasion, location, sentinel node number, serum DHL level, lymph nodes dissected and extracapsular spread.

Results: 67 patients, 35 women and 32 men with a mean of 66 years, 22% had metastases in lymph nodes from complementary lymphadenectomy, 19% of them with extracapsular spread; no relationship with the Breslow level. Extracapsular spread in the sentinel node, lymphadenectomy time, and perineural invasion in the primary tumor were prognostic factors for non-sentinel node metastasis.

Conclusions: In this series, 22% of the patients with a sentinel node-positive have metastases in the non-sentinel nodes, 19% of them with extracapsular spread, which justifies complementary lymphadenectomy.