High risk of virus-associated cancer death for those with AIDS

Non-HIV-related cancers are an important cause of death in patients with AIDS, Italian researchers report in the November 1^st edition of Clinical Infectious Diseases. Cancers not classified as AIDS-defining caused 7% of all deaths.

The investigators also found that these patients with AIDS were almost seven times more likely to die because of these cancers than HIV-negative individuals in the general population. In addition, cancers associated with viral infections were identified as an important cause of death in those with AIDS.

“This analysis provides estimates of the excess risk of non-AIDS-defining cancers among people with AIDS in the HAART [highly active antiretroviral therapy] era”, comment the investigators.

Thanks to antiretroviral therapy the prognosis of many patients with HIV is now considered near-normal. There has been a marked fall in the incidence of AIDS-defining illnesses, including a decline in the number of patients who are diagnosed with the AIDS-related cancers Kaposi’s sarcoma and non-Hodgkin lymphoma.

However, several studies have shown that the number of deaths attributable to non-AIDS-related cancers in patients with HIV has increased in recent years.

Investigators wished to see if this had been the case in Italy. Their study involved 10,392 patients who were diagnosed with AIDS between 1999 and 2006. All were Italian citizens aged 15 years and older. The investigators also compared the non-AIDS-related cancer mortality in these patients to that seen in the wider Italian population.

The patients were followed for a median of 37 months, and 35, 224 person-years of follow-up were available for analysis.

A total of 3209 patients died. Their median age was 42 years, 79% were men and 51% had a history of injecting drug use.

Death was caused by a non-AIDS-defining cancer in 7% of patients. The most common cancers were those of the lung (58 cases), liver (28), Hodgkin lymphoma (28), and head and neck (18).

Overall, patients with HIV were seven times more likely to die of a non-AIDS-defining cancer than age and sex matched individuals in the general Italian population.

Moreover, the investigators noted that mortality rates due to cancers caused by viral infections were especially high in those with AIDS.

For example, the mortality rate for anal cancer, caused by certain strains of the genital wart virus HPV, was 240 times higher in those with AIDS. Hodgkin lymphoma is caused by Epstein-Barr virus, and the mortality rate attributable to this cancer was 174 times higher for patients with AIDS than individuals in the general population. Infection with hepatitis C virus can lead to liver cancer, and patients with AIDS were eleven times more likely to die of this malignancy than those in the wider population.

The investigators emphasise that their “findings refer only to people with AIDS, who may not be representative of HIV-infected people.”

They conclude, “our findings...highlight the importance of monitoring the cancer burden on mortality of people with AIDS, offering specialists in infectious diseases and oncologists an additional means of evaluation of the death threat of non-AIDS-defining cancers to people with AIDS.”