Norra MacReady
August 2, 2010 (Vienna, Austria) — Life expectancy is increasing for people with HIV and AIDS, and with it, cancer risk and incidence, Eric A. Engels, MD, MPH, reported here at AIDS 2010: XVIII International AIDS Conference.
This means that cancer prevention and treatment among people infected with HIV will become more and more important in the years ahead, said Dr. Engels, senior investigator at the Division of Cancer Epidemiology and Genetics at the National Cancer Institute.
In an analysis of data collected by the Centers for Disease Control and Prevention during 15 years from 15 regions of the United States, Dr. Engels and coauthors found that the proportion of the US AIDS population aged 50 years or more increased from 8% of 93,802 people in 1991 to 29% of 399,762 people in 2005.
During the same time period, the incidence of non-AIDS-defining cancers increased, from 416 in 1991 to 2437 in 2005, with a total of 76,558 cancers in this cohort.
In contrast, AIDS-defining cancers such as Kaposi's sarcoma and non-Hodgkin's lymphoma decreased from 7284 cases in 1993 to 1736 cases in 2005.
Cases of anal cancer increased from 18 in 1991 to 358 in 2005, and cases of prostate cancer increased from 10 to 123 from 1991 to 2005, largely as a result of rising rates of those malignancies, Dr. Engels said during an oral abstract session. The rates of lung cancer and Hodgkin's lymphoma remained relatively stable, but the absolute number of cases increased from 112 to 478 and from 72 to 169, respectively.
The authors also estimated cancer incidence between 2004 and 2007 for people in 34 states who were HIV-positive but did not have AIDS. In that population, 4388 cancers occurred, including 381 anal cancers, 892 lung cancers, and 327 cases of Hodgkin's lymphoma.
Immunosuppression and coinfection with the human papillomavirus may explain, in part, the dramatic rise in the number of anal cancer cases, Dr. Engels told Medscape Medical News.
These findings are "in large part due to the increasing number of people living with HIV infection and the fact that they are getting older," he said. "Non-AIDS-defining cancers are now roughly as common as AIDS-defining cancers [in this population] and represent a priority for cancer prevention, screening, and treatment."
Treatment challenges among people with HIV and AIDS include immunosuppression and drug interactions between highly active antiretroviral therapy and chemotherapy. In addition, "many HIV-infected people present late to care, which can impair their response to cancer treatment," the investigator pointed out.
Strides in medications and management are allowing patients in this population "to enter the prime years for cancer development," noted Susan E. Krown, MD, head of the Human Papilloma Virus Working Group of the AIDS Malignancy Consortium at the National Cancer Institute.
Patients infected with HIV "are also more likely than HIV-uninfected individuals to smoke and to have coinfections, such as HPV and hepatitis B and C, that increase the likelihood of certain cancers. A particular challenge is to learn how best to manage the sometimes profound interactions between cancer therapeutic agents and antiretroviral drugs," said Dr. Krown, who is also a medical oncologist at the Memorial Sloan-Kettering Cancer Center in New York City. She was not involved in this research.
"The link between non-AIDS-defining cancers and HIV is not entirely clear, but appears to be related to factors beyond HIV and the associated immunosuppression," said Michael Fisch, MD, MPH, chairman of the Department of General Oncology at the M.D. Anderson Cancer Center in Houston, Texas. Along with lifestyle factors such as smoking and sexual behavior, "testosterone replacement, and perhaps even adherence to screening recommendations, may play a role in the association" between HIV and non-AIDS-defining cancers, he added. Dr. Fisch was also not involved in this study.
He took a brighter view of treatment than Dr. Krown. "In most instances, standard cancer therapy can be safely provided to HIV-infected patients," he told Medscape Medical News. "And I am optimistic that similar potential exists for the HIV population to reduce suffering and death due to cancer through standard screening and advice related to lifestyle and behavioral modifications."
Dr. Engels, Dr. Krown, and Dr. Fisch have disclosed no relevant financial relationships.
AIDS 2010: XVIII International AIDS Conference: Abstract WEAB 0101. Presented Wednesday, July 21, 2010
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