[Methodological issues and first results of a record linkage between AIDS and Cancer Registries in Italy].

We report herein, the first results of a record linkage between the Italian AIDS Registry and 13 population-based Cancer Registries (about 8-million population in 1991). An anonymous linkage process was carried out on about 339,000 cancer notifications and 6,067 AIDS ones reported between 1982 and 1994. Out of 243 Kaposi's sarcomas (KS) below age 50 years recorded at either type of registry, 90 (37%) were reported as such by both. Sixty-eight percent of individuals with KS at Cancer Registries could be identified at the AIDS Registry. Sixty-two percent of individuals with KS and 65% of individuals reported as having non-Hodgkin's lymphoma (NHL) at RAIDS could be also found at Cancer Registries. Among 6,067 persons with AIDS 15-69 years old, observed and expected numbers of cancer and age-standardised incidence ratios (SIR) on a total of 25,759 person-years were computed. Significantly increased SIR was found for Hodgkin's disease (8.9; 95% CI: 4.4-16.0), invasive carcinoma of the cervix uteri (15.5; 95% CI: 4.0-40.1), and non-melanomatous skin cancer (3.0, 95%, CI: 1.3-5.9). As in previous studies, KS and NHL were greatly increased (SIR = 1,300 and 59, respectively). The risk for all cancer types, after exclusion of KS and NHL, was approximately twice the risk of the general population. An increased SIR of Hodgkin's disease in persons with AIDS is thus confirmed, though many-fold smaller than for NHL. An association with invasive carcinoma of the cervix is also shown at a population level. These data indicate the potential of AIDS and Cancer Registries for improving cancer assessment in individuals with HIV/AIDS and elucidating the role of immune system on cancer onset.