A study of over 20 years of cancer incidences show the therapy may have broken the trend.
Certain cancer risks in HIV patients in the US have been reduced due to the emergence of antiretroviral therapies (ART) in the last 20 years.
A new study has found that several virus-related cancers, as well as lung cancer, have declined in risk since 1996 — when ART was expanded in HIV therapy regimens. The result is an indication of improved patient care, as well as a change in the prevalence of risk factors caused by HIV patients.
Particular cancers, including Kaposi sarcoma, lymphomas, and cervical, anal, and liver cancers, have been known to have an elevated presence in HIV patients for a long time, study lead author Raul Hernandez-Ramirez, MSc, told MD Magazine.
“Incidence of Kaposi sarcoma and non-Hodgkin lymphoma have dramatically declined since the introduction of effective antiretroviral therapy in 1996,” Hernandez-Ramirez, a PhD student at the Yale University School of Public Health, said. “However, trends for other cancers have been less clear, and studies covering years in the more modern treatment era are scarce.”
Hernandez-Ramirez pointed to HIV’s effect on patient immunosuppression — as well as an increased prevalence of cancer-causing viruses, smoking, and alcohol use — as contributive to the elevated cancer risks in HIV patients.
In a study of US population-based HIV and cancer registries, researchers assessed 448,258 HIV patients identified in Colorado, Connecticut, Georgia, Maryland, Michigan, New York, Puerto Rico, and Texas from 1996 to 2012. From that population, 21,294 (4.75%) incident cancers were documented in that time — an increase from the general population, according to calculated standardized incidence ratios (SIRs).
SIRs were calculated through dividing the observed number of cancer cases in HIV patients by the expected population number. The SIR differences were tested by patients’ AIDS status and over time with the Poisson regression.
The increased cancer patient rate was particularly higher versus non-HIV population for incidences of Kaposi’s sarcoma, non-Hodgkin lymphoma, virus-related cancers, and lung cancer.
In tracking the difference over 2 decades with multivariable adjustments, researchers found elevated risks in several cancers after AIDS onset. However, SIRs “decreased significantly” for Kaposi’s sarcoma, 2 subtypes of non-Hodgkin lymphoma, and cancers of the anus, liver, and lung.
Other prominent cancer incidences prominent in the HIV population remained elevated, while SIRs did not increase over time for any cancer itself.
“For several virus-related cancers and lung cancer, declining risks over time in HIV-infected people probably reflect the expansion of ART since 1996,” researchers wrote. “Additional efforts aimed at cancer prevention and screening in people with HIV are warranted.”
The National Cancer Institute (NCI), a funding source for the study, reported on its website that combination ART (cART), while a more efficient HIV therapy, does not entirely restore patients’ immune system functioning.
“The introduction of cART has not reduced the incidence of all HIV-related cancers, and in fact there has been an increase in non—AIDS-defining cancers,” the website notes. “For example, the incidence of liver and anal cancer may be increasing among HIV-infected individuals.”
Due to patients’ therapy access and ART efficacy, the HIV population has become larger and older in average age over years, according to NCI. The fast growing age group of HIV patients are aged 40 years and older, and they are more susceptible to developing both HIV-associated and non-associated cancers.
Even HIV patients to have survived cancer following treatment are still at a disadvantage, Hernandez-Ramirez said.
“Survival after a cancer diagnosis may be worse in patients with HIV than in other patients, in part because of HIV-related immunosuppression, which may increase cancer growth and spread,” Hernandez-Ramirez said.
This particular area is in need of further research, he said.
The study, "Cancer risk in HIV-infected people in the USA from 1996 to 2012: a population-based, registry-linkage study," was published online in The Lancet.