The effectiveness of antiretroviral therapy has enabled patients with HIV to live long enough to have high lifetime risks for several types of cancer. The finding has important clinical implications for cancer screening, as well as primary prevention, according to the results of a study funded by the National Institutes of Health and published in the Annals of Internal Medicine.
In particular, the “high cumulative incidences by age 75 years for Kaposi sarcoma, non-Hodgkin lymphoma [NHL], and lung cancer support early and sustained antiretroviral therapy and smoking cessation,” wrote Michael J. Silverberg, PhD, MPH, of Kaiser Permanente Division of Research, Oakland, California, and many colleagues representing schools of medicine and public health, universities, the Centers for Disease Control and Prevention, HIV/AIDS organizations, and other entities.
Time trends in cumulative cancer incidence by age 75 years were compared for 86,620 persons with HIV and 196,987 uninfected adults. All were 18 years of age or older and were followed between 1996 and 2009 in 16 cohorts from the United States and Canada. “Most participants were men, and fewer than one-half were white,” the researchers reported.
The authors noted that a higher cancer burden among patients with HIV is “due to both impaired immune function, including chronic inflammation, and a higher prevalence of risk factors, including smoking and viral coinfections.”
Cumulative Incidences by Cancer Type
The investigators determined that the cumulative incidences of anal, colorectal, and liver cancers are increasing among persons with HIV because they are living longer. The highest cumulative incidences were observed for Kaposi sarcoma, NHL, and lung cancer. Patients with HIV had an approximately 1 in 25 lifetime risk for developing Kaposi sarcoma, NHL, or lung cancer.
Among the nine cancer types chosen as endpoints, cumulative cancer incidence by age 65 and 75 was higher among persons with HIV for all but three—colorectal cancer, melanoma, and oral cavity/pharyngeal cancer. “Cumulative incidences of cancer by age 75 years for persons with and without HIV, respectively, were as follows: Kaposi sarcoma, 4.4% and 0.01%; NHL, 4.5% and 0.7%; lung cancer, 3.4% and 2.8%; anal cancer, 1.5% and 0.05%; colorectal cancer, 1.0% and 1.5%; liver cancer, 1.1% and 0.4%; Hodgkin lymphoma, 0.9% and 0.09%; melanoma, 0.5% and 0.6%; and oral cavity/pharyngeal cancer, 0.8% and 0.8%.”
The high lung cancer incidence and high smoking rates among persons with HIV “suggest that smokers with HIV should be compelling candidates for screening” with low-dose computed tomography, the authors stated. They called for research to clarify the benefits vs harms resulting from a high-false positive rate due to an elevated incidence of lung infections and other pulmonary diseases.
In addition, “the increase in anal cancer risk highlights the need for further evidence about the harms and benefits of anal dysplasia screening. Although there are no formal guidelines, it would be prudent for physicians to be alert for early signs and symptoms of Kaposi sarcoma and NHL,” the researchers wrote.
“Our results also have clinical implications for primary prevention,” the authors wrote. This includes targeted smoking cessation interventions and the “highly effective” HPV vaccine licensed in 2011 for prevention of anal cancer.
“The increasing risk for liver cancer over time indicates a need to ensure universal hepatitis B vaccination for persons with HIV who are hepatitis B–seronegative, as already recommended, and to provide treatment of hepatitis B infection using antiretroviral therapy regimens with antihepatitis B activity and of hepatitis C infection with recently approved interferon-free therapies,” the authors added.
Early and sustained antiretroviral therapy remains the only known approach to prevent Kaposi sarcoma and NHL and “possibly other cancer types linked to immunosuppression or inflammation,” the investigators noted. They also called for research “to follow up on observational studies that suggest that statin use by persons with HIV may reduce cancer risk, presumably because of the anti-inflammatory effect.” ■
Silverberg MJ, et al: Ann Intern Med 163:507-518, 2015.