Prognostic Factors, Treatment, and Survival in Primary Cutaneous Mucinous Carcinoma: A SEER Database Analysis.

Abstract

Limited information exists on the demographics, tumor characteristics, and treatment in primary cutaneous mucinous carcinoma (PCMC). The authors sought to describe prognostic factors, incidence rates, and the subsequent primary malignancy (SPM) risk in patients with PCMC. Primary cutaneous mucinous carcinoma cases in the National Cancer Institute's Surveillance, Epidemiology, and End Results data (1972-2013) were analyzed to provide demographic, cancer-related, and treatment information and to calculate incidence and mortality. Patients were stratified by stage (local, regional, distant disease) for comparison. The risk of developing an SPM was calculated. Four hundred eleven PCMC cases were identified. The age-adjusted incidence was 0.04 cases per 100,000-person years. Blacks were disproportionately affected by PCMC (0.048; 95% confidence interval, 0.034-0.065; p < .001). Approximately 67.4% of patients had local disease, 10.5% had regional disease, and 5.8% had distant disease. Primary cutaneous mucinous carcinoma-specific mortality was independent of sex, age, race, primary site, histologic tumor grade, tumor size, tumor stage, or treatment. The overall frequency of developing a second primary malignancy was not increased in patients with PCMC. Although PCMC occurs with equally in both sexes, it may be more common in African Americans than previously recognized. Although eyelid PCMC may have a higher rate of distant metastasis, all patients need close follow-up.