Despite treatment, elderly patients with cancer who are HIV-positive had worse outcomes than those without the infection in a recent study.
Previous research has shown that mortality rates following a cancer diagnosis are higher for people who are infected with HIV than those not infected with the virus, but few studies have closely examined the reasons for this poorer survival rate. One factor that remains under-researched in clinical studies is the higher mortality rate among HIV-infected patients with cancer who receive various levels of cancer treatment. This is an important issue because lower cancer treatment rates have been reported for HIV-infected patients across multiple studies, and the type and timing of cancer treatments could be an important driver of the cancer survival deficits consistently reported in HIV-infected patients.
To address this research gap, Anna E. Coghill, PhD, MPH, and colleagues had a study published in JAMA Oncology that compared cancer-specific mortality in patients with cancer who were either infected or uninfected with HIV and adjusted the data based on receipt of specific cancer treatments. The study was funded by the intramural research program at the National Cancer Institute.
“Although previous studies showing that HIV-infected cancer patients are more likely to die from their cancer than HIV-uninfected cancer patients, we felt it was important to also take into account detailed information on the treatments patients may have received,” says Dr. Coghill. “This includes the type or timing of treatment.”
Taking a Closer Look
For the study, Dr. Coghill and colleagues used SEER–Medicare linked data to evaluate 288 HIV-infected patients aged 65 years and older with a cancer diagnosis and compared them with more than 300,000 HIV-uninfected patients in the United States between 1996 and 2012. The study cohort included patients diagnosed with non-advanced colorectal, lung, prostate, or breast cancer who received stage-appropriate cancer treatment during the year after their cancer diagnosis. The primary outcomes assessed in the study included overall mortality, cancer-specific mortality, and relapse or cancer-specific mortality after initial treatment.
According to the results, HIV-infected patients had significant elevations in overall mortality when compared with HIV-uninfected patients for cancers of the colorectum, prostate, and breast (Table). The investigators observed persistent survival disparities after adjusting for first-year cancer treatment, suggesting that healthcare differences may not be the sole driver of poor cancer outcomes in people with HIV.
Importantly, the link between HIV and poor cancer-specific outcomes was notably consistent for HIV-infected patients with prostate and breast cancer. When compared with men not infected with HIV, men who were HIV-infected and had prostate cancer experienced higher rates of prostate-specific mortality. Similar results were seen for HIV-infected women with breast cancer, with HIV-infected women being nearly twice as likely to die of breast cancer and significantly more likely to experience disease relapse or death after successfully completing initial cancer therapy.
Assessing the Implications
Recently, a study published in Annals of Internal Medicine found that the proportion of adults aged 65 years and older living with HIV is projected to increase from 8.5% in 2010 to 21.4% in 2030, with prostate and lung cancer expected to emerge as the most common types by 2030. Authors of this study concluded that cancer will continue to be an important comorbid condition in people with HIV and noted that expanded access to HIV therapies and cancer prevention, screening, and treatment is needed.
“As the HIV population continues to age, the association of HIV infection with poor breast and prostate cancer outcomes will become more important,” Dr. Coghill says. “Based on results from our study, we are stressing the need for more research on clinical strategies to improve outcomes for HIV-infected patients with cancer.” Future work should also consider using more precise approaches to examining HIV in relation to poor cancer outcomes after initial cancer therapy, including examination of the degree of HIV severity or specific HIV therapies administered.