AIDS increases risk of non-AIDS-related cancers
Immune system suppression in HIV-positive individuals increases the risk of developing some types of cancer that are not specifically related to AIDS, according to a study published in the September 15th issue of the American Journal of Epidemiology.
Kaposi’s sarcoma, non-Hodgkins’s lymphoma and invasive cervical cancer have been identified as AIDS-related cancers, but small studies have also revealed an increased incidence of other malignant diseases in patients with HIV.
Using New York AIDS and cancer registries, Brian Gallagher and colleagues at the New York State Department of Health compared 1981-1994 cancer rates of 122, 993 people with AIDS with those of the general state population. Overall, 12, 698 people with AIDS were diagnosed with cancer during this time period, 88.7% of whom were male and 11.3% of whom were female. Among the 10, 083 men with AIDS and cancer, 84.6% were diagnosed between the ages of 25 and 49, 77.9% were non-black, 22.1% were black, 76.6% were men who had sex with men or MSM combined with injection drug users and 17.7% were IDUs. Among the women, 86.1% were diagnosed between the ages of 25 and 49, 55.2% were non-black, 44.8% were black, 53.8% were IDUs, and 31.5% were women who had heterosexual contact.
Researchers calculated the sex and HIV risk group-specific standardized incidence ratios (SIRs), post-AIDS relative risks and trends of relative risks to determine cancer risk of the AIDS group.
AIDS-related cancer and non-AIDS-related cancer risks
The risks for AIDS-related cancers in people with AIDS compared to the general population were as follows:
- Kaposi’s sarcoma: 97.5 times higher in men and 202.7 times higher in women;
- non-Hodgkin’s lymphoma: 37.4 times higher in men and 54.6 times higher in women;
- invasive cervical cancer: 9.1 times higher in women.
For all non-AIDS-related cancers combined, the SIR was 2.6 for men with AIDS and 2.2 for women with AIDS, and the relative risk was 3.1 for men and 2.9 for women. The cancers with significant SIRs included the following:
- tongue (male, 1.8; female, 7.1);
- gum and other mouth (male, 1.9; female, 11.1);
- rectum, rectosigmoid and anus (male, 3.3; female, 3.0);
- larynx (male, 1.9; female, 5.9);
- trachea, bronchus, and lung (male, 3.3; female, 7.5);
- skin, excluding Kaposi’s sarcoma (male, 20.9; female, 7.5);
- brain and central nervous system (male, 3.1; female, 3.4);
- Hodgkin’s disease (male, 8.0; female, 6.4);
- multi-myeloma (male, 2.7; female, 7.2).
Significantly elevated SIRs also included the following:
- pharynx (2.0);
- stomach (1.8);
- liver (5.1);
- testis (1.5);
- endocrine gland (3.8);
- connective tissue in men (5.6);
- oesophagus in women (8.7);
- leukaemia’s in women (6.1).
Cancers with significantly elevated overall SIRs were evaluated by HIV exposure group. Researchers found that men who contracted HIV through homosexual contact had higher SIRs for cancers of the anus, brain and central nervous system and connective tissues, and men who had become infected via drug injection had higher SIRs for cancers of the trachea, bronchus and lung and digestive system. For women who contracted the virus through heterosexual contact, the SIRs were higher for Hodgkin’s disease, cancers of the brain, central nervous system and digestive system and invasive cervical cancer. Among women who became infected via injection drug use, SIRs were higher for cancers of the trachea, bronchus, lung, oral cavity and pharynx. The researchers concluded, “We have confirmed that cancer occurs in excess for AIDS-related cancers and for (certain) non-AIDS-related cancers”. “Cancer is a high morbidity and mortality complication of HIV infection, and evaluating HIV-infected patients for (non-AIDS-related cancers) is important.” Gallagher said. He added that physicians should closely monitor their AIDS patients and consider other factors that could increase their risk for cancer. In the study, researchers noted that the relationship between HIV and cancer is not well understood, and new research is needed in light of new drug therapies that have significantly extended the lives of people with AIDS.
Gallagher B et al. Cancer incidence in New York State acquired immunodeficiency syndrome patients. Am J Epidemiol 2001 Sep 15;154(6):544-56.
Source: Kaiser Daily HIV/AIDS Reports