In HIV/AIDS Patients, Common Cancers Up, AIDS-Defining Cancers Down

Neil Osterweil

April 13, 2011

April 13, 2011 — Although incidence rates of AIDS-defining cancers such as Kaposi's sarcoma have plummeted since the introduction of highly active antiretroviral therapy (HAART) in the 1990s, other more common cancers are filling the void, report investigators from the National Cancer Institute (NCI) in Rockville, Maryland.

From 1991 to 1997, as the number of Americans with AIDS increased, the number of AIDS-defining cancers showed a sharp decline, and continued to decrease more gradually in subsequent years. However, at the same time, in people with either HIV or AIDS, the number of non-AIDS-defining cancers — particularly anal, liver, prostate, and lung cancers — increased about 3-fold, according to Meredith S. Shiels, PhD, MHS, from the Infections and Immunoepidemiology Branch of the NCI's Division of Cancer Epidemiology and Genetics, and colleagues. Their study was published online April 11 in the Journal of the National Cancer Institute.

The increase in non-AIDS-related cancer among people with HIV infection is a byproduct of the success of HAART. Namely, people are living with HIV and AIDS far longer than in the early days of the epidemic, and developing cancers that rise in incidence with age, according to the authors.

"The growing burden of non-AIDS-defining cancers highlights the need for cancer prevention and early detection among HIV-infected people. In particular, programs focusing on smoking cessation (to prevent lung and other cancers) and the prevention and treatment of hepatitis B and C viral infections (to prevent liver cancer) should be targeted toward HIV-infected people," they write.

An oncologist with expertise in AIDS-related cancers told Medscape Medical News that the findings confirm what she and her colleagues have seen in recent years.

"What we were seeing clinically is that cancers such as lung cancer and anal cancer were increasing in this population. I think this article validates that and I think it's important because it points out that half the cancers currently are things that are non-AIDS-defining," said Ariela Noy, MD, from Memorial Sloan-Kettering Cancer Center in New York City, and chair of the Lymphoma Working Group for the AIDS Malignancy Consortium. Dr. Noy was not involved in the study.

AIDS Population Grows, Ages

The NCI investigators obtained incidence rates for individual cancer types from the ongoing HIV/AIDS Cancer Match Study, which links 15 American population-based HIV and cancer registries. They used surveillance data from the US Centers for Disease Control and Prevention to estimate the population living with HIV and AIDS.

To estimate the incidence of AIDS-defining cancers (Kaposi's sarcoma, non-Hodgkin's lymphoma, and cervical cancer) and non-AIDS-defining cancers from 1991 to 2005, they multiplied cancer incidence rates and AIDS population counts stratified by year, age, sex, race/ethnicity, transmission category, and AIDS-relative time (time since onset of AIDS).

There was a more than 4-fold increase in the number of people living with AIDS in the United States from 1991 to 2005 (96,179 to 413,080 people). Over the same period, there was a "substantial" age shift in the AIDS patient population, largely due to an increase in the number of people living with the disease who were 40 years or older, and an increase in the number of people who had AIDS for 10 years or more.

Comparing the 5 years from 1991 to 1995 with the 5 years from 2001 to 2005, the authors saw that the estimated number of AIDS-defining cancers fell from 34,587 to 10,325 — a more than 3-fold decline (P for trend < .001). During the same time period, non-AIDS-defining cancers increased slightly more than 3-fold — from 3,193 to 10,059 (P for trend < .001).

Changes Over Time in Non-AIDS-Defining Cancers

Cancer Type 1991 to 1995 2001 to 2005
Anal 206 1564
Liver 116 583
Prostate 87 759
Lung 875 1882
Hodgkin's Lymphoma 426 897

The investigators also looked at a more limited set of data from 34 American states that tracked HIV-infected people who had not yet developed AIDS (946,936 person-years from 2004 to 2007). They estimated an incidence of 2191 non-AIDS-defining cancers during that period, including 154 anal cancers, 454 lung cancers, and 166 breast cancers.

Their findings suggest that people living with HIV should be screened for common cancers on the basis of age-specific recommendations and included in clinical trials of cancer therapies.

Dr. Noy told Medscape Medical News that the AIDS Malignancy Consortium is involved in clinical trials of therapies for cancers that are disproportionately prevalent in patients with HIV-infection, including anal and liver cancer and Hodgkin's lymphoma. In addition, an intergroup study of advanced Hodgkin's lymphoma, led by the Southwest Oncology Group, has enrolled patients living with HIV.

The study was funded by the Intramural Research Program of the NCI. The authors are NCI employees. The AIDS Malignancy Consortium receives NCI funding.

J Natl Cancer Inst. Published online April 11, 2011. Abstract