Sentinel Lymph Node Biopsy for Evaluation and Treatment of Patients With Merkel Cell Carcinoma: The Dana-Farber Experience and Meta-analysis of the Literature

OBJECTIVE To determine the diagnostic accuracy and usefulness of sentinel lymph node biopsy (SLNB) and computed tomographic scans in the initial evaluation and treatment of patients with Merkel cell carcinoma (MCC). DESIGN Single-institution case series and literature-based case-level meta-analysis. SETTING Academic cutaneous oncology clinic. PATIENTS Sixty-one adults with biopsy-proven MCC (30 who had undergone SLNB) plus 92 cases from the literature of patients who had undergone SLNB. MAIN OUTCOME MEASURES Relapse-free survival. RESULTS In 122 patients with no nodal disease found by physical examination, SLNB findings revealed nodal involvement in 39 cases (32%). At 3 years, the recurrence rate for those with a positive SLNB was 3 times (60%) higher than for those with a negative SLNB (20%; P = .03). Patients with a positive SLNB who received adjuvant nodal therapy had a relapse-free survival rate of 51% at 3 years (n = 26) compared with 0% for patients who did not receive nodal therapy (n = 3; P