Mucosal melanomas in the racially diverse population of California

Background Mucosal melanomas are rare, poorly understood neoplasms without a consensus standard of care. Objective We sought to define mucosal melanoma tumor characteristics and the racial/ethnic attributes of patients with mucosal melanomas. Methods We analyzed 130,920 cutaneous melanomas and 1919 mucosal melanomas recorded in the population-based California Cancer Registry from 1988 to 2013. Results Although only 1% of melanomas occurring in nonHispanic whites were mucosal, other racial/ethnic groups had a higher proportion of mucosal melanomas (15% for Asian/Pacific Islanders, 9% for nonHispanic blacks, and 4% for Hispanics). Anorectal mucosal melanomas were most common in female Asian/Pacific Islanders, whereas genitourinary mucosal melanomas were highest in nonHispanic whites, and head and neck tumors were most common among Hispanics. Stage at presentation was not uniform among racial/ethnic groups, with Asian/Pacific Islanders having the highest rates of metastasis. Limitations The lack of a standardized staging system for mucosal melanomas confounds classification and knowledge regarding metastasis. Small sample size limits comparative analysis across race, stage, site, and depth. Conclusion Mucosal melanomas differ by race/ethnicity with regard to anatomic site, stage, and depth. Because early detection offers the best chance of increased survival, greater awareness will aid clinicians who care for patients at risk for these aggressive tumors.