“In the HAART (highly active antiretroviral therapy) era, the incidence of AIDS-defining malignancies has decreased. However, we have become more concerned with non-AIDS-defining malignancies. I believe most commonly we are seeing lung, liver, and anal cancer, in addition to Hodgkin lymphoma. Because of this trend, there needs to be intense collaboration between HIV specialists and medical oncologists. Because many HIV drugs could impact the metabolism of chemotherapeutic agents, and vice versa, the two specialists must work much more closely together in cancer-affected HIV patients,” said David Prelutsky, MD, medical director of Southampton Healthcare, St. Louis, Missouri.
Michael Silverberg, PhD, an epidemiologist at Kaiser Permanente Northern California, Oakland, California, agrees with Dr. Prelutsky. He and his colleagues have found that HIV-positive individuals have an earlier mean age of cancer diagnosis, but similar stage at diagnosis for several common cancers compared to HIV-negative individuals.4 The California researchers identified 22,081 HIV-positive patients and 230,069 age-matched and sex-matched HIV-negative individuals who were enrolled in Kaiser Permanente California between 1996 and 2009. The analysis considered prostate, anal, lung, and colorectal cancers. These were the four most commonly non-AIDS-defining cancers (NADC) diagnosed among the HIV-positive individuals in this study.
The investigators found that HIV-positive individuals had a younger age at diagnosis for anal, lung, and colorectal cancer, but not for prostate cancer. Dr. Silverberg said stage at diagnosis was similar by HIV status for all cancer types. However, there was a nonsignificant trend for more advanced stage (stage 3 or 4) at diagnosis for anal cancer (39% for HIV-positive patients vs 16% for HIV-negative patients). The same was true for lung cancer (stage 4; 64% for HIV-positive patients vs 51% for HIV-negative patients).
The investigators also looked at 5-year survival rates and found that HIV-positive patients did not fare as well for prostate cancer (84% for HIV-positive patients vs 91% for HIV-negative patients) and lung cancer (8% for HIV-positive patients vs 22% for HIV-negative patients). “It needs further study. There could be some infectious origin. The survival difference was pretty significant. It was 22% vs 8%, which is really striking and low survival,” Dr. Silverberg told ChemotherapyAdvisor.com. “We think it is HIV and its sequelae and associated immunodeficiency that are resulting in higher risk of lung cancer and other cancers.”
Is There a Common Factor Contributing to Growing Cancer Burden among HIV-Positive Individuals?
Other investigators have also found that lung cancer risk is substantially elevated in HIV-infected individuals.5 However, investigators at the National Cancer Institute (NCI) found that the increased lung cancer incidence was unrelated to HIV-induced immunosuppression. Their study found that incidence of lung cancer still remained higher among HIV-positive individuals even after adjustment for smoking, suggesting additional factors are involved.
“HIV infected patients have an elevated risk of lung cancer compared to the general population. Much of this is due to smoking, but there may be an added effect due to the HIV infection, since in our study, lung cancer risk was higher than predicted on the basis of smoking alone,” study investigator Eric Engels, MD, MPH, of the National Cancer Institute, Rockville, Maryland, told ChemotherapyAdvisor.com. “Lung cancer will become an increasing problem as HIV-infected people live longer.”