Survival by sex and HIV status in patients with anal cancer in the USA between 2001 and 2019: a retrospective cohort study.

ABSTRACT

BACKGROUND: The risk of anal cancer is increased among people with HIV, particularly men who have sex with men. Estimating survival by HIV status and sex and identifying groups at high risk is crucial for documenting prognostic differences between populations. We aimed to compare all-cause and anal cancer-specific survival in patients with anal cancer with and without HIV, stratified by sex, and to identify predictors of survival, stratified by HIV status. METHODS: In this retrospective cohort study, we used data from the HIV/AIDS Cancer Match Study of 13 population-based HIV and cancer registries throughout the USA. We included individuals aged 20-79 years diagnosed with invasive anal cancer between 2001 and 2019. To estimate associations between HIV status and both all-cause and anal cancer-specific mortality overall, we used Cox proportional hazards models, adjusting for year of and age at diagnosis, sex, race and ethnicity, histology, cancer stage, region, and treatment. We also calculated sex-specific adjusted hazard ratios (HRs). By HIV status, we identified characteristics associated with mortality. Models among people with HIV were further adjusted for AIDS status and HIV transmission risk group. FINDINGS: Between Jan 1, 2001, and Dec 31, 2019, 1161 (43·6%) of 2662 patients with anal cancer and HIV and 7722 (35·4%) of 21 824 patients without HIV died. HIV was associated with a 1·35 times (95% CI 1·24-1·47) increase in all-cause mortality among male patients and a 2·47 times (2·10-2·90) increase among female patients. Among patients with HIV, all-cause mortality was increased among non-Hispanic Black individuals (adjusted HR 1·19, 95% CI 1·04-1·38), people with AIDS (1·36, 1·10-1·68), people who inject drugs (PWID; 1·49, 1·17-1·90), patients with adenocarcinoma (2·74, 1·82-4·13), and those with no or unknown surgery treatment (1·34, 1·18-1·53). HIV was associated with anal cancer-specific mortality among female patients only (1·52, 1·18-1·97). Among patients with HIV, anal cancer-specific mortality was increased among patients with adenocarcinoma (3·29, 1·89-5·72), those with no or unknown treatment (1·59, 1·17-2·17), and PWID (1·60, 1·05-2·44). INTERPRETATION: HIV was associated with all-cause mortality among patients with anal cancer, especially women. Anal cancer-specific mortality was elevated among female patients with HIV. As screening for anal cancer becomes more widespread, examining the effects of screening on survival by HIV status and sex is crucial. FUNDING: US National Cancer Institute Intramural Research Program.