Fw: NATAP/CROI: Non-AIDS Cancers & Age

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Most Non-AIDSCancers Not Diagnosed at Earlier Age in People With AIDS17th Conference on Retroviruses andOpportunistic Infections, February 16-19, 2010, San FranciscoMark MascoliniMost non-AIDS cancers do not arise at a significantlyyounger age in people with AIDS than in the general population, according toresults of a National Cancer Institute (NCI) study [1]. Two non-AIDSmalignancies--anal cancer and lung cancer--did arise at a slightly butsignificantly earlier ages in people AIDS than in the general population, asdid two AIDS cancers. The NCI investigators suggest that several factors mayaccount for the age difference with these four cancers--including HIV-inducedimmune dysfunction, and smoking or having sex at a younger age by people with HIV.To gauge the impact of HIV and AIDS on cancerrisk, the NCI team analyzed data from the HIV/AIDS Cancer Match Study, whichlinks 15 US HIV and cancer registries including over 338,000 people whoreceived care from 1980 through 2008. This analysis focused on people with anAIDS diagnosis and follow-up data from 4 to 60 months after that diagnosis. Four in 5 people in the AIDS group were male,51% were black, and median age at AIDS diagnosis was 37 years. The registries cataloged21,477 cancers during 916,343 person-years of follow-up after the AIDSdiagnosis. The most common diagnoses were two AIDS cancers, Kaposi sarcoma in10,281 people and non-Hodgkin lymphoma in 6668. The next three most commondiagnoses were non-AIDS cancers--913 lung cancers, 346 anal cancers, and 318Hodgkin lymphomas. There were 168 diagnoses of cervical cancer, another AIDScancer.Understanding different rates of AIDS andnon-AIDS cancers in people with HIV and the general population depends on understandingthe sharply different age distribution of these two populations in the databaseanalyzed. The general population had an even age distribution--with similarproportions of people at each age--to about age 40. At that point, theproportion of people at each age fell slowly and evenly in the generalpopulation. In contrast, the AIDS population included very few people under 20.>From that age to the late 30s, the proportion at each age rose sharply. After apeak in the late 30s, there was a mirror-image drop in the proportion of AIDSpatients in each age group to about age 65. The AIDS group included few peopleover 65. People 65 or older contributed 13% of person-years in the generalpopulation versus 1% in the AIDS group.For most cancers analyzed, people with AIDSwere about 15 to 30 years younger at cancer diagnosis than the generalpopulation. For anal cancer, median age at diagnosis was 42 in the AIDS groupversus 64 in the general population (P < 0.001). For lung cancer median age at diagnosis was 49 with AIDSversus 68 in the general population (P < 0.001). For Hodgkin lymphoma, age at diagnosis was significantlyolder in the AIDS population (41 versus 35, P < 0.001). But after statisticians accounted for thedramatically different age distribution in the two populations, differences inage at diagnosis became very small or disappeared. After that age-distributionadjustment, the NCI researchers confirmed slightly but significantly earlier ageat diagnosis for Kaposi sarcoma, non-Hodgkin lymphoma, anal cancer, and lung cancer.Age at diagnosis of Hodgkin lymphoma was significantly older for people withAIDS.The investigators suggest that earlier age atdiagnosis of certain cancers in people with AIDS "may represent an effectof HIV on these cancers possibly by inducing loss of immune control ofinfection with oncogenic viruses." But behavioral factors could also be atplay. For example, people with HIV may start smoking earlier than people in thegeneral population, or they may start having sex at a younger age and thus heightentheir risk of exposure to cancer-causing viruses. The study is limited in notbeing able to assess the impact of these and other cancer risk factors.Older age at diagnosis of Hodgkin lymphoma in people with AIDS, theresearchers say, "represents a strong increase in the risk of Epstein-Barrvirus (EBV)-positive cases that occur at older ages, rather than a shift ofEBV-negative cases to older ages."For most cancers," the NCIresearchers conclude, "there is no difference in age at cancer diagnosisamong persons with AIDS compared to the general population." Apparent agedifferences between those populations "arise largely due to differences inthe underlying populations at risk of cancer."References1. Shiels M, Pfeiffer R,Engels E. Do people with AIDS develop cancer at younger ages than the generalpopulation? 17th Conference on Retroviruses and Opportunistic Infections.February 16-19, 2010. San Francisco. Abstract 757.