Risk factors for positive sentinel lymph nodes in head and neck melanoma — a survival analysis

INTRODUCTION: Sentinel lymph node biopsy is the gold standard procedure for head and neck cutaneous melanoma staging. OBJECTIVE: To evaluate the technical aspects, positivity and prognostic effect of the cervico-facial sentinel lymph node biopsy. METHODS: Retrospective, unicentric study. From 2009 to 2014, 49 patients with cutaneous melanoma of the head and neck underwent surgery at Instituto do Câncer do Estado de São Paulo (ICESP). RESULTS: Of the 49 patients, 5 had cervical metastasis at the moment of admission. Clark, Breslow and mitotic index were predictors of death. Among the 31 patients undergoing sentinel lymph node biopsy, 3 had positive sentinel lymph nodes (9.7%). Deaths were recorded in two of the cases with positive sentinel lymph nodes (66.6%), and in 5 (17.8%) of the patients with negative lymph nodes. The mean Breslow index was 11.3 mm for primary melanomas with positive sentinel lymph nodes and 4.3 mm for those with negative sentinel lymph nodes. Positivity was associated with Clark and Breslow levels. Malar location showed a protective effect on prognosis. The mean survival for patients with a mitotic index <3.5 was 181 months and 63.4 months for those with a mitotic index >3.5. CONCLUSION: The frequency of positive sentinel lymph node biopsy in patients with malignant melanoma of the head and neck was lower than in other studies, although the sample consisted of individuals with advanced melanomas. The mitotic index was important for prognosis prediction.