A new study has found that people living with HIV are at an increased risk of both first and second primary cancer incidence.
The association between HIV and an increased risk of cancer is well-documented, with people in the United States having an approximately 50% increased rate of being diagnosed with cancer compared to the general population. Now, new research is pointing to an increased risk for both first and secondary cancer incidence among the patient population.
The increased risk of cancer is due in part to people living with HIV living longer, thanks to advances like antiretroviral therapy. As these patients live longer, with compromised immune systems, they become more susceptible to both AIDS-defining and non-AIDS—defining cancers.
“The combination of older age, extended duration of immunosuppression, longer latency period for oncogenic viruses, and ongoing environmental exposures such as tobacco and alcohol use, puts people living with HIV at heightened risk for malignancies over time,” wrote the researchers of the study.
Compromised immune systems, combined with the fact that cancer survivors are more likely to be diagnosed with a second malignancy, puts people living with HIV at an even greater risk of developing a second primary cancer, according to the study of 22,623 patients diagnosed with HIV between January 1, 1990, and December 21, 2010.
Among these patients, there were 4545 incident primary cancers, accounting for 4144 first primary cancers, 372 second primary cancers, 26 third primary cancers, and 3 fourth or later primary cancers. People living with HIV had higher standardized incidence ratios for 14 first primary cancers, including: Kaposi sarcoma, non-Hodgkin lymphoma, cervical cancer, anal cancer, vulvar cancer, Hodgkin lymphoma, eye and orbit cancer, lip cancer, penile cancer, liver cancer, miscellaneous cancer, testicular cancer, tongue cancer, and lung cancer.
Second primary cancer risk was increased for Kaposi sarcoma, anal cancer, non-Hogkin lymphoma, Hodgkin lymphoma, and liver cancer. The median time between the first and second cancer was 2.1 years. Over time, first and second primary AIDS-defining cancer incidence declined while second primary non-AIDS—defining cancer incidence increased.
For the more common first primary cancers, Kaposi sarcoma was typically followed by non-Hodgkin lymphoma and anal cancer or both. Similarly, non-Hodgkin lymphoma as first primary cancer was typically followed by Kaposi sarcoma and anal cancer. Hodgkin lymphoma was mainly followed by non-Hodgkin lymphoma, Kaposi sarcoma, anal cancer, prostate cancer, and tongue cancer.
“All first and second cancers that we identified in excess were due, at least in part, to oncogenic viruses, which are highly prevalent in people with HIV,” wrote the researchers. “The persistence of these pathogens or the damage caused by them, and in the increased speed of progression of these viruses in people with HIV compared to people without HIV, places people living with HIV at continued increased risk of virus-related cancers.”
Higher risk can also be attributed to lifestyle factors, such as smoking, they added. Cigarette smoking accounted for 19% of all cancers during 2000 and 2015, as well as 94% of lung cancer and 32% of anal cancer.
However, the researchers noted lower second primary cancer incidence for testicular cancer, kidney cancer, and prostate cancer.
Hessol N, Whittemore H, Vittinghoff E, et al. Incidence of first and second primary cancers diagnosed among people with HIV, 1985-2013: a population-nased, registry linkage study [published online September 20, 2018]. Lancet HIV. doi: https://doi.org/10.1016/S2352-3018(18)30179-6.