Cancer incidence in people with AIDS in Italy

People with HIV/AIDS (PWHA) have increased risk of some cancers. The introduction of highly active antiretroviral therapies (HAART) has improved their life expectancy, exposing them to the combined consequences of aging and of a prolonged exposure to cancer risk factors. The aim of this study was to estimate incidence rates (IR) in PWHA in Italy, before and after the introduction of HAART, after adjusting for sex and age through direct standardization. An anonymous record linkage between Italian AIDS Registry (21,951 cases) and Cancer Registries (17.3 million, 30% of Italian population) was performed. In PWHA, crude IR, sex- and age-standardized IR and age-specific IR were estimated. The standardized IR for Kaposi sarcoma and non-Hodgkin lymphoma greatly declined in the HAART period. Although the crude IR for all non-AIDS-defining cancers increased in the HAART period, standardized IR did not significantly differ in the 2 periods (352 and 379/100,000, respectively). Increases were seen only for cancer of the liver (IR ratio = 4.6, 95% CI: 1.3–17.0) and lung (IR ratio = 1.8, 95% CI: 1.0–3.2). Age-specific IRs for liver and lung cancers, however, largely overlapped in the 2 periods pointing to the strong influence of the shift in the age distribution of PWHA on the observed upward trends. In conclusion, standardized IRs for non-AIDS-defining cancers have not risen in the HAART period, even if crude IRs of these cancers increased. This scenario calls, however, for the intensification of cancer-prevention strategies, notably smoking cessation and screening programs, in middle-aged HIV-patients. Individuals who are infected with HIV have an increased risk of cancer.1–3 Since 1982, Kaposi sarcoma (KS), non-Hodgkin lymphoma (NHL) and—since 1993—invasive cervical cancer have been part of the clinical definition of AIDS.4 Evidence of a cancer excess among people with HIV/AIDS (PWHA) compared to the general population has accumulated over the years for several other cancers, in particular Hodgkin lymphoma, cancers of the ano-genital tract, liver and lung.1–3 HIV infection leads, through immune dysregulation, to increased replication or persistence of oncogenic viruses (in particular, Epstein Barr virus, KS-herpesvirus and human papillomaviruses).5 Moreover, PWHA have higher prevalence of oncogenic virus infection, compared to the general population. Although the introduction of highly active antiretroviral therapies (HAART) in 1996 has greatly lowered the risk of KS and NHL in PWHA,6, 7 other cancers have not shown equally favorable trends.8–11 In addition, improved survival started exposing PWHA to the combined consequences of aging and of the prolonged exposure to cancer risk factors such as oncogenic virus infections and tobacco smoking. Only a few studies reported population-based estimates of age-adjusted incidence rates (IR) of cancers other than KS and NHL among PWHA.12, 13 This study intends to contribute to the current knowledge showing an update of cancer incidence in a population-based study from a country severely hit by AIDS and where women and injecting-drug users are proportionally more common among AIDS patients than in most other developed countries. A record linkage between the National AIDS Registry and all Italian population-based cancer registries was carried out with the aim to estimate changes in cancer IRs in PWHA in Italy before and after the introduction of HAART, after adjusting for age with direct standardization. On account of the substantial aging of PWHA after HAART availability, special attention was paid to standardize IRs by sex and age and to compare age-specific IRs. AIDS: acquired immunodeficiency syndrome; CI: confidence interval; HAART: highly active antiretroviral therapies; HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: human immunodeficiency virus; IR: incidence rates; KS: Kaposi sarcoma; NADC: non-AIDS-defining cancer; NHL: non-Hodgkin lymphoma; PWHA: people with HIV/AIDS; PY: person-years