Cancer Risk among Adults Living with HIV in Ontario.

Cancer is an important comorbidity and healthcare concern for people living with the human immunodeficiency virus (HIV). Researchers have quantified the burden of cancer among people living with HIV in Ontario using administrative and registry-linked data held at ICES. Findings showed that although cancer incidence has declined over time, people living with HIV remain at a greater risk for cancers with infectious causes compared with HIV-negative people. There is a need for comprehensive HIV care that includes cancer prevention strategies.

Associations of CD4 Cell Count Measures With Infection-Related and Infection-Unrelated Cancer Risk Among People With HIV.

BACKGROUND: People with HIV are at higher risk of infection-related cancers than the general population, which could be due, in part, to immune dysfunction. Our objective was to examine associations between 4 CD4 count measures as indicators of immune function and infection-related and infection-unrelated cancer risk. SETTING: We conducted a cohort study of adults with HIV who were diagnosed with cancer in Ontario, Canada. Incident cancers were identified from January 1, 1997 to December 31, 2020. METHODS: We estimated adjusted hazard ratios (aHR) for the associations between CD4 measures (baseline CD4, nadir CD4, time-updated CD4, time-updated CD4:CD8) and cancer incidence rates using competing risk analyses, adjusted for socio-demographic factors, history of hepatitis B or C infection, baseline viral load, smoking, and alcohol use. RESULTS: Among 4771 people with HIV, contributing 59,111 person-years of observation, a total of 549 cancers were observed. Low baseline CD4 (<200 cells/µL) (aHR 2.08 [95% CI: 1.38 to 3.13], nadir (<200 cells/µL) (aHR 2.01 [95% CI: 1.49 to 2.71]), low time-updated CD4 (aHR 3.52 [95% CI: 2.36 to 5.24]) and time-updated CD4:CD8 ratio (<0.4) (aHR 2.02 [95% CI: 1.08 to 3.79]) were associated with an increased rate of infection-related cancer. No associations were observed for infection-unrelated cancers. CONCLUSIONS: Low CD4 counts and indices were associated with increased rates of infection-related cancers among people with HIV, irrespective of the CD4 measure used. Early diagnosis and linkage to care and high antiretroviral therapy uptake may lead to improved immune function and could add to cancer prevention strategies such as screening and vaccine uptake.

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.

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.

The burden of cancer among people living with HIV in Ontario, Canada, 1997-2020: a retrospective population-based cohort study using administrative health data.

BACKGROUND: With combination antiretroviral therapy (ART) and increased longevity, cancer is a leading cause of morbidity among people with HIV. We characterized trends in cancer burden among people with HIV in Ontario, Canada, between 1997 and 2020. METHODS: We conducted a population-based, retrospective cohort study of adults with HIV using linked administrative health databases from Jan. 1, 1997, to Nov. 1, 2020. We grouped cancers as infection-related AIDS-defining cancers (ADCs), infection-related non-ADCs (NADCs) and infection-unrelated cancers. We calculated age-standardized incidence rates per 100 000 person-years with 95% confidence intervals (CIs) using direct standardization, stratified by calendar period and sex. We also calculated limited-duration prevalence. RESULTS: Among 19 403 adults living with HIV (79% males), 1275 incident cancers were diagnosed. From 1997-2000 to 2016- 2020, we saw a decrease in the incidence of all cancers (1113.9 [95% CI 657.7-1765.6] to 683.5 [95% CI 613.4-759.4] per 100 000 person-years), ADCs (403.1 [95% CI 194.2-739.0] to 103.8 [95% CI 79.2-133.6] per 100 000 person-years) and infection-related NADCs (196.6 [95% CI 37.9-591.9] to 121.9 [95% CI 94.3-154.9] per 100 000 person-years). The incidence of infection-unrelated cancers was stable at 451.0 per 100 000 person-years (95% CI 410.3-494.7). The incidence of cancer among females increased over time but was similar to that of males in 2016-2020. INTERPRETATION: Over a 24-year period, the incidence of cancer decreased overall, largely driven by a considerable decrease in the incidence of ADC, whereas the incidence of infection-unrelated cancer remained unchanged and contributed to the greatest burden of cancer. These findings could reflect combination ART-mediated changes in infectious comorbidity and increased life expectancy; targeted cancer screening and prevention strategies are needed.

A two-day workshop reviewing Canadian provincial and national HIV care cascade indicators, reporting, challenges, and recommendations.

BACKGROUND: The HIV care cascade is an indicators-framework used to assess achievement of HIV clinical targets including HIV diagnosis, HIV care initiation and retention, initiation of antiretroviral therapy, and attainment of viral suppression for people living with HIV. METHODS: The HIV Care Cascade Research Development Team at the CIHR Canadian HIV Trials Network Clinical Care and Management Core hosted a two-day virtual workshop to present HIV care cascade data collected nationally from local and provincial clinical settings and national cohort studies. The article summarizes the workshop presentations including the indicators used and available findings and presents the discussed challenges and recommendations. RESULTS: Identified challenges included (1) inconsistent HIV care cascade indicator definitions, (2) variability between the use of nested UNAIDS's targets and HIV care cascade indicators, (3) variable analytic approaches based on differing data sources, (4) reporting difficulties in some regions due to a lack of integration across data platforms, (5) lack of robust data on the first stage of the care cascade at the sub-national level, and (6) inability to integrate key socio-demographic data to estimate population-specific care cascade shortfalls. CONCLUSION: There were four recommendations: standardization of HIV care cascade indicators and analyses, additional funding for HIV care cascade data collection, database maintenance and analyses at all levels, qualitative interviews and case studies characterizing the stories behind the care cascade findings, and employing targeted positive-action programs to increase engagement of key populations in each HIV care cascade stage.

HISTORIQUE: La cascade des soins du VIH est un cadre d'indicateurs utilisé pour évaluer l'atteinte des cibles cliniques du VIH, y compris le diagnostic, le début et le maintien des soins, le début du traitement antirétroviral et l'obtention de la suppression virale chez les personnes qui vivent avec le VIH. MÉTHODOLOGIE: L'équipe de développement de la recherche sur la cascade des soins du VIH située au noyau de perfectionnement de la gestion clinique du Réseau canadien pour les essais VIH des IRSC a organisé un atelier virtuel de deux jours pour présenter les données sur la cascade des soins du VIH amassées dans les milieux cliniques locaux et provinciaux et les études de cohorte de tout le pays. L'article résume les présentations d'ateliers, y compris les indicateurs utilisés et les observations disponibles, et présente les défis et recommandations abordés. RÉSULTATS: Les défis mis en évidence incluaient 1) les définitions hétérogènes des indicateurs de la cascade des soins sur le VIH, 2) la variabilité entre l'utilisation des cibles d'ONUSIDA imbriquées et les indicateurs de cascade des soins du VIH, 3) des approches analytiques variables d'après diverses sources de données, 4) la déclaration des difficultés dans certaines régions à cause de l'absence d'intégration entre les plateformes de données, 5) l'absence de données vigoureuses sur la première étape de la cascade des soins infranationaux et 6) l'incapacité d'intégrer les principales données sociodémographiques pour évaluer les écueils de la cascade des soins populationnels. CONCLUSION: Quatre recommandations ont été formulées : la standardisation des indicateurs et des analyses de la cascade des soins du VIH, le financement supplémentaire de la collecte de la cascade des soins du VIH, l'entretien des bases de données et les analyses à tous les échelons, les entrevues qualitatives et les études de cas qui caractérisent les histoires qui se cachent derrière les observations tirées de la cascade des soins et le recours à des programmes d'action positive ciblés pour accroître la participation de populations clés à chaque étape de la cascade des soins du VIH.