Time trends in cancer incidence in Australian people living with HIV between 1982 and 2012.

OBJECTIVES: The aim of the study was to describe time trends in cancer incidence in people living with HIV (PLHIV) in Australia between 1982 and 2012. METHODS: A population-based prospective study was conducted using data linkage between the national HIV and cancer registries. Invasive cancers identified in PLHIV were grouped into AIDS-defining cancers (ADCs), infection-related non-ADCs (NADCs), and non-infection-related NADCs. Crude and age-standardized incidence rates of cancers were calculated and compared over five time periods: 1982-1995, 1996-1999, 2000-2004, 2005-2008 and 2009-2012, roughly reflecting advances in HIV antiretroviral therapy. Standardized incidence ratios (SIRs) compared with the Australian general population were calculated for each time period. Generalized linear models were developed to assess time trends in crude and age-standardized incidences. RESULTS: For ADCs, the crude and age-standardized incidences of Kaposi sarcoma and non-Hodgkin lymphoma substantially declined over time (P-trend < 0.001 for all) but SIRs remained significantly elevated. For infection-related NADCs, there were significant increases in the crude incidences of anal, liver and head and neck cancers. Age-standardized incidences increased for anal cancer (P-trend = 0.002) and liver cancer (P-trend < 0.001). SIRs were significantly elevated for anal cancer, liver cancer and Hodgkin lymphoma. For non-infection-related NADCs, the crude incidence of colorectal, lung and prostate cancers increased over time, but age-standardized incidences remained stable. CONCLUSIONS: Continuous improvements and high coverage of antiretroviral therapy have reduced the incidence of ADCs in PLHIV in Australia. Clinical monitoring of anal and liver cancers in people living with HIV should be performed, given the increasing incidence of these cancers.

Sexual behaviours associated with incident high-risk anal human papillomavirus among gay and bisexual men.

OBJECTIVE: High-risk human papillomavirus (HRHPV) causes anal cancer, which disproportionately affects gay and bisexual men (GBM). We examined sexual behaviours associated with incident anal HRHPV in an observational cohort study of GBM in Sydney, Australia. METHODS: GBM aged 35 years and above were enrolled in the Study of the Prevention of Anal Cancer. Detailed information on sexual practices in the last 6 months, including receptive anal intercourse (RAI) and non-intercourse receptive anal practices, was collected. Anal human papillomavirus (HPV) testing was performed at the baseline and three annual follow-up visits. Risk factors for incident HRHPV were determined by Cox regression using the Wei-Lin-Weissfeld method. RESULTS: Between 2010 and 2015, 617 men were recruited and 525 who had valid HPV results at baseline and at least one follow-up visit were included in the analysis. The median age was 49 years (IQR 43-56) and 188 (35.8%) were HIV-positive. On univariable analysis, incident anal HRHPV was associated with being HIV-positive (p<0.001), having a higher number of recent RAI partners regardless of condom use (p<0.001 for both), preference for the receptive position during anal intercourse (p=0.014) and other non-intercourse receptive anal sexual practices, including rimming, fingering and receptive use of sex toys (p<0.05 for all). In multivariable analyses, being HIV-positive (HR 1.46, 95% CI 1.09 to 1.85, p=0.009) and reporting condom-protected RAI with a higher number of sexual partners (p<0.001) remained significantly associated with incident HRHPV. When stratified by recent RAI, non-intercourse receptive anal practices were not associated with incident HRHPV in men who reported no recent RAI. CONCLUSION: GBM living with HIV and those who reported RAI were at increased of incident anal HRHPV. Given the substantial risk of anal cancer and the difficulty in mitigating the risk of acquiring anal HRHPV, HPV vaccination should be considered among sexually active older GBM. TRIAL REGISTRATION NUMBER: ANZCTR365383.