Racial/Ethnic Disparities in Survival Among Women Diagnosed with Invasive Cancer of the Anal Canal: an Analysis of Surveillance, Epidemiology, and End Results (SEER) Data

Objective: To identify differences in survival among women diagnosed with cancer of the anal canal from varying racial and ethnic backgrounds.

Methods: Data from the Surveillance, Epidemiology and End Results (SEER) registry between the years of 1975 and 2016 were analyzed, which included 19,048 women with cancer of the anal canal. Multivariable Cox proportional hazard regression (HRs) was performed to examine the relative risk of dying among women with anal cancer. Multivariable odds ratios (ORs) with 95% confidence intervals (CIs) were used to examine odds of highly fatal disease (death within 12 months from diagnosis).

Results: Non-Hispanic Black women (n = 1694) had greater risk of dying when compared with non-Hispanic White women (n = 15,821) with anal cancer (HR = 1.26, CI: 1.17-1.35), independent of other prognostic indicators. Stratifying by age at diagnosis, risk of death was highest for non-Hispanic Black women diagnosed younger than age 50 years compared with non-Hispanic White women of similar age (HR = 1.60, CI: 1.34-1.89), and lowest for Hispanic women (n = 1533) older than 74 years at diagnosis (HR = 0.80, CI: 0.69-0.92). Stratifying by stage at diagnosis, disparities were not observed. When comparing across years of diagnoses, non-Hispanic Black women consistently had poorer survival compared with non-Hispanic White women diagnosed in the same year intervals. Finally, non-Hispanic Black women had greater odds of highly fatal disease (OR = 1.23, CI: 1.08-1.40) compared with non-Hispanic White women.

Conclusion: Non-Hispanic Black women with anal cancer continue to experience poorer survival compared with non-Hispanic White women, whereas disparities were not identified for Hispanic women.