Survival outcomes of rare cutaneous malignancies within an insured cohort of patients, 1988-2018.

Background: There are limited survival data on cutaneous angiosarcoma (CAS), dermatofibrosarcoma protuberans (DFSP), Merkel cell carcinoma (MCC), and sebaceous carcinoma (SC).

Objective: To analyze survival trends in CAS, DFSP, MCC, and SC among a racially diverse, insured cohort of patients.

Methods: Using data from the Kaiser Permanente Southern California Cancer Registry, we identified adults diagnosed with CAS, DFSP, MCC, or SC between January 1, 1988 and December 31 2018, followed through December 31, 2021.

Results: Our cohort consisted of 83 diagnoses of CAS, 490 diagnoses of DFSP, 411 diagnoses of MCC, and 249 diagnoses of SC. Our analysis revealed no significant differences in overall or disease-specific 1000 person-years mortality rates among our populations of non-Hispanic Whites, Hispanics, African American/Blacks, and Asian American/Pacific Islanders diagnosed with CAS, DFSP, MCC, or SC. On multivariate analysis, controlling for patient and tumor characteristics, there was similarly no increased risk of overall mortality for minorities diagnosed with CAS, DFSP, MCC, or SC.

Limitations: Retrospective nature of the analysis and small sample size.

Conclusion: Contrary to existing literature, our results show a notable lack of racially driven survival disparities among insured individuals with CAS, DFSP, MCC, and SC, emphasizing the importance of health care coverage.