Background: Limited information exists on the demographics, tumor characteristics, and treatment in primary cutaneous mucinous carcinoma (PCMC).
Objective: The authors sought to describe prognostic factors, incidence rates, and the subsequent primary malignancy (SPM) risk in patients with PCMC.
Methods: 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.
Results: 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.
Conclusion: 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.