Immune Status in Merkel Cell Carcinoma: Relationships With Clinical Factors and Independent Prognostic Value.

Immune status was independently prognostic for the OS of patients with localized MCC. The etiology of IS may be associated with differential survival outcomes. Multiple adverse prognostic factors were associated with increased likelihood of IS. Immune status, and potentially the etiology of IS, may be useful prognostic factors to consider for future MCC staging systems.