Cancer risk increased with AIDS

It is known that the immunosuppression associated with HIV infection and AIDS leads to a significantly increased risk for Kaposi’s sarcoma (KS), non-Hodgkin’s Lymphoma (NHL) and cervical cancer. It is not well known, however, whether other malignancies are also associated with HIV disease and AIDS.

In a study published in the Journal of the American Medical Association, researchers from the AIDS-Cancer Match Registry Study Group evaluated cancer data from 302,834 adult patients, 15 to 69 years of age, diagnosed with AIDS between 1978 and 1996. The study included all cancer types, except non-melanoma skin cancers. The relative risk of cancer was determined for 60 months before to 27 months after AIDS onset. The relative risk for each cancer was defined as the ratio of observed to expected cancers derived from contemporaneous population-based incidence rates.

As expected, the investigators found that KS, NHL and cervical cancer occurred at significantly higher rates in HIV-infected patients. KS occurred in 9.9% of men and 0.8% of women. Among men, the incidence of KS was found to be highest in gay men, who had a relative risk of 267.2. Among women, KS was highest among those who were infected by a bisexual man, with a relative risk of 2044.2. NHL occurred in 3.4% of men and 1.5% of women, with relative risks of 71.7 and 88.4, respectively. Cervical cancer occurred in 0.7% of women, with a relative risk of 5.2.

Four thousand four hundred and twenty-two invasive cancers, other than KS, NHL and cervical cancer, occurred in this population. The overall relative risk of these cancers was 2.7, and this higher risk was present in both HIV-infected men and women. 6 cancers appeared to be potentially influenced by the immunosuppression associated with HIV infection and AIDS. These included Hodgkin’s disease, lip cancer, lung cancer, soft tissue malignancies, penile cancer, and testicular seminoma, with relative risks of 11.5, 3.1, 4.8, 3.3, 3.9 and 2.0, respectively. In this population, lung cancer was the most frequently diagnosed non-AIDS-defining cancer.

This study rather convincingly shows that when compared with the general population HIV-infected patients are at increased risk of cancer. This increased risk is highest regarding the AIDS-related cancers, KS, NHL and cervical CA, but also extends to other cancers. Some of these cancers are almost certainly related to well-defined risk factors other then HIV-infection, including smoking (lung and lip cancers), and infection with human papillomavirus (cervical and penile cancers), human herpesvirus 8 (KS) or Epstein-Barr virus (Hodgkin’s disease), but immunosuppression appears to play a role as well, with its overall impact dependent upon the cancer type.

Finally, these data, collected prior to the widespread use of HAART, may actually underestimate the incidence of these and other cancers in HIV-infected patients. As some studies have demonstrated, cancer may become an increasingly important problem as survival time increases in HAART-treated, HIV-infected patients.

M Frisch and others. Association of Cancer With AIDS-Related Immunosuppression in Adults. JAMA. 2001; 285:1736-45.