As the population of people living with HIV in the United States ages, the burden of cancer for these patients is expected to shift away from cancers linked to AIDS and toward malignancies that affect the general population, according to a new study led by a University of North Carolina at Chapel Hill researcher.
In findings presented at the 2017 American Association for Cancer Research Annual Meeting on April 5, UNC-Chapel Hill researcher Jessica Y. Islam, in collaboration with the National Cancer Institute (NCI) and Centers for Disease Control and Prevention (CDC), reports the total number of HIV-positive cancer patients in the United States is projected to decrease through 2030, with a significant decrease in cancers linked to the advanced stage of HIV infection - AIDS - while frequencies of other cancers, such as those of the lung and prostate, will increase.
"Declines in cancer incidence rates, particularly for AIDS-defining cancers, are likely driven by widespread treatment with modern antiretroviral therapies, which reduce immune suppression and decrease risk of some cancers," said Islam, a doctoral student in the UNC Gillings School of Global Public Health. "Effective treatment also increases the life expectancy of people living with HIV."
HIV is a virus that attacks the body's immune system. AIDS, or acquired immunodeficiency syndrome, is the advanced stage of infection that occurs when opportunistic infections or cancers occur. The widespread use of highly active antiretroviral therapy (HAART) has led to an increase in survival in people with HIV, researchers report, resulting in an aging population. Islam and collaborators estimated the proportion of the HIV population above age 65 to increase to 21.4 percent by 2030, up from 4.1 percent in 2006.
Future cancer risk and burden for HIV-positive people were estimated using age-specific cancer incidence data from the NCI HIV/AIDS Cancer Match Study, and projected HIV prevalence data from the CDC. They found that rates by age are projected to decrease across all age groups for non-Hodgkin lymphoma, cervical cancer, lung cancer and all other cancers, and, for some groups, Kaposi sarcoma, Hodgkin lymphoma, and colon cancer. Prostate cancer rates are projected to continue to increase.
When estimating cancer burden -- the total number of patients living with cancer -- investigators projected an overall decrease from 7,900 cases in 2010, to 6,500 cases in 2030. The researchers expect to see a shift in burden of cancer types, with a strong decline in the numbers of cases of cancers that define AIDS -- predominantly Kaposi sarcoma and non-Hodgkin lymphoma. Meanwhile, they expect to see an increase, by 600, in non-AIDS defining cancers, predominately prostate, lung, liver, and anal cancer.
"It is critical to understand both incidence rates and burden over time, as rates capture changes in cancer risk, and burden quantifies the actual number of cancer cases expected to occur," said the study's senior author Meredith S. Shiels, PhD, an investigator with the NCI Division of Cancer Epidemiology and Genetics, Infections and Immunoepidemiology Branch. "For example, lung cancer rates are expected to decrease in the future, but the burden is expected to increase due to the growing number of older people living with HIV."
The study's findings have implications for cancer prevention and control for this group, the researchers said.
"Cancer will continue to be an important co-morbidity in this population," Shiels said. "Anticipating the types of cancers that are expected to be most common in the future can direct targeted prevention, early detection, and control efforts, including smoking cessation, treatment for hepatitis C and B viruses, age-appropriate cancer screening, and continued widespread treatment with antiretroviral therapy."