Trends in infection-related and infection-unrelated cancer incidence among people with and without HIV infection in Ontario, Canada, 1996-2020: a population-based matched cohort study using health administrative data

Ioana A Nicolau; Rahim Moineddin; Tony Antoniou; Jennifer D Brooks; Jennifer L Gillis; Claire E Kendall; Curtis Cooper; Michelle Cotterchio; Kate Salters; Marek Smieja; Abigail E Kroch; Joanne D Lindsay; Colleen Price; Anthony Mohamed; Ann N Burchell

doi:10.9778/cmajo.20220230

Trends in infection-related and infection-unrelated cancer incidence among people with and without HIV infection in Ontario, Canada, 1996-2020: a population-based matched cohort study using health administrative data

CMAJ Open. 2023 Oct 10;11(5):E894-E905. doi: 10.9778/cmajo.20220230. Print 2023 Sep-Oct.

Authors

Affiliations

¹ Dalla Lana School of Public Health (Nicolau, Brooks, Cotterchio, Kroch), University of Toronto; Li Ka Shing Knowledge Institute (Nicolau, Antoniou, Lindsay, Mohamed, Burchell), St. Michael's Hospital, Unity Health Toronto; Department of Family and Community Medicine (Moineddin, Antoniou, Burchell), University of Toronto; ICES Central (Moineddin, Antoniou, Burchell); Canadian Cancer Society (Gillis), Toronto, Ont.; Bruyère Research Institute (Kendall); Department of Family Medicine (Kendall), University of Ottawa; Institut du Savoir Montfort (Kendall); Clinical Epidemiology Program (Kendall), Ottawa Hospital Research Institute; ICES uOttawa (Kendall); Ottawa Hospital Research Institute (Cooper), Ottawa, Ont.; Ontario Health (Cancer Care Ontario) (Cotterchio), Toronto, Ont.; British Columbia Centre for Excellence in HIV/AIDS (Salters), Vancouver, BC; Department of Pathology and Molecular Medicine (Smieja), McMaster University, Hamilton, Ont.; Ontario HIV Treatment Network (Kroch), Toronto, Ont.; Canadian HIV/AIDS and Chronic Pain Society (Price), Ottawa, Ont.
² Dalla Lana School of Public Health (Nicolau, Brooks, Cotterchio, Kroch), University of Toronto; Li Ka Shing Knowledge Institute (Nicolau, Antoniou, Lindsay, Mohamed, Burchell), St. Michael's Hospital, Unity Health Toronto; Department of Family and Community Medicine (Moineddin, Antoniou, Burchell), University of Toronto; ICES Central (Moineddin, Antoniou, Burchell); Canadian Cancer Society (Gillis), Toronto, Ont.; Bruyère Research Institute (Kendall); Department of Family Medicine (Kendall), University of Ottawa; Institut du Savoir Montfort (Kendall); Clinical Epidemiology Program (Kendall), Ottawa Hospital Research Institute; ICES uOttawa (Kendall); Ottawa Hospital Research Institute (Cooper), Ottawa, Ont.; Ontario Health (Cancer Care Ontario) (Cotterchio), Toronto, Ont.; British Columbia Centre for Excellence in HIV/AIDS (Salters), Vancouver, BC; Department of Pathology and Molecular Medicine (Smieja), McMaster University, Hamilton, Ont.; Ontario HIV Treatment Network (Kroch), Toronto, Ont.; Canadian HIV/AIDS and Chronic Pain Society (Price), Ottawa, Ont. ann.burchell@unityhealth.to.

Abstract

Background: People with HIV infection are at higher risk for certain cancers than the general population. We compared trends in infection-related and infection-unrelated cancers among people with and without HIV infection.

Methods: We conducted a retrospective population-based matched cohort study of adults with and without HIV infection using linked health administrative databases in Ontario, Canada. Participants were matched on birth year, sex, census division (rurality), neighbourhood income quintile and region of birth. We followed participants from cohort entry until the earliest of date of cancer diagnosis, date of death, Nov. 1, 2020, or date of loss to follow-up. Incident cancers identified from Jan. 1, 1996, to Nov. 1, 2020, were categorized as infection-related or-unrelated. We examined calendar periods 1996-2003, 2004-2011 and 2012-2020, corresponding to the early combination antiretroviral therapy (cART), established cART and contemporary cART eras, respectively. We used competing risk analyses to examine trends in cumulative incidence by calendar period, age and sex, and cause-specific hazard ratios (HRs).

Results: We matched 20 304 people with HIV infection to 20 304 people without HIV infection. A total of 2437 cancers were diagnosed, 1534 (62.9%) among infected people and 903 (37.0%) among uninfected people. The risk of infection-related cancer by age 65 years for people with HIV infection decreased from 19.0% (95% confidence interval [CI] 15.6%-22.3%) in 1996-2011 to 10.0% (95% CI 7.9%-12.1%) in 2012-2020. Compared to uninfected people, those with HIV infection had similar HRs of infection-unrelated cancer but increased rates of infection-related cancer, particularly among younger age groups (25.1 [95% CI 13.2-47.4] v. 1.9 [95% CI 1.0-3.7] for age 18-39 yr v. ≥ 70 yr); these trends were consistent when examined by sex.Interpretation: We observed significantly higher rates of infection-related, but not infection-unrelated, cancer among people with HIV infection than among uninfected people. The elevated rate of infection-related cancer in 2012-2020 highlights the importance of early and sustained antiretroviral therapy along with cancer screening and prevention measures.