A systematic review of patients with Merkel cell carcinoma of the head and neck and a negative sentinel lymph node biopsy

Background: A negative sentinel lymph node biopsy (SLNB) from patients with head and neck Merkel cell carcinoma (HNMCC) may allow the patient to avoid further adjunctive therapies. However, there is considerable regional variability of lymphatic drainage from primary sites involving the head and neck, and Merkel cell carcinoma (MCC) has aggressive biologic behavior. Objective: The primary aim of this systematic review was to document the incidence of regional recurrence and mortality from HNMCC patients after a negative SLNB. Methods: A systematic search of the English literature was conducted via Ovid Medline and Embase from inception until 2013 and the Cochrane Central Register of Controlled Trials from 1991 to January 2014. Results: Twenty-three studies, with a total of 81 patients matched the inclusion criteria. The incidence of regional recurrence from the entire cohort was 12.3%, and there was a 5% mortality rate. The mean follow-up time, excluding the 30 patients who did not have individual follow-up times specified, was 32.8 months. Limitations: This review included studies had variable follow-up durations and treatments for MCC. Conclusions: Despite negative pathologic staging of the neck using SLNB in HNMCC patients, there is still a high incidence of regional recurrence and mortality, over a short follow-up period