August 08, 2019
By Marilynn Larkin
NEW YORK (Reuters Health) - Older HIV-infected adults with cancer had worse overall and cancer-specific outcomes than their HIV-uninfected peers in an observational study.
"The strongest results (were) apparent for breast cancer and, to a lesser extent, colorectal and prostate cancers," Dr. Eric Engels of the US National Cancer Institute in Bethesda, Maryland told Reuters Health by email. "These results support that immunosuppression associated with HIV infection makes these cancers behave more aggressively, for example, by impairing immune control of tumors."
"Clinicians should make sure that HIV-infected cancer patients receive adequate therapy for their malignancy in accord with current treatment guidelines," he added.
Dr. Engels and colleagues analyzed Surveillance, Epidemiology, and End Results (SEER) - Medicare linked data and identified 308,268 patients, age 65 and older (about 54% men) with nonadvanced cancers of the colorectum, lung, prostate, or breast diagnosed between 1996 and 2012.
All patients received standard, stage-appropriate cancer treatment during the year after their cancer diagnosis.
As reported online August 1 in JAMA Oncology, 288 of the patients (.093%) had HIV. These patients had significant elevations in the overall mortality rate compared with HIV-uninfected patients for cancers of the colorectum (hazard ratio, 1.73), prostate (HR, 1.58), and breast (HR, 1.50).
Further, cancer-specific mortality was elevated for cancers of the prostate (HR, 1.65) and breast (HR, 1.85).
Compared with their HIV-uninfected peers, HIV-infected men with prostate cancer also had significantly higher rates of relapse or death (HR, 1.32), as did HIV-infected women with breast cancer (HR, 1.63).
Summing up, the authors state, "In this nationally representative sample of the aging HIV population in the United States, HIV was associated with an elevated risk of overall and cancer-specific mortality. HIV infected patients with prostate or breast cancer appeared to be at particularly increased risk of worse outcomes, even after adjustment for available data on first-year cancer treatments."
Dr. Engels said, "We continue to investigate the relationship between immunity and cancer. A major focus of our research concerns the epidemiology of cancer in immunosuppressed patients with HIV infection and other medical conditions, because these conditions predispose patients to develop cancer and appear to worsen the outcomes following a cancer diagnosis."
Dr. Thomas Uldrick, deputy head of Global Oncology at Fred Hutchinson Cancer Research Center in Seattle, Washington, told Reuters Health the study "raises several important questions."
"The study accounted for receipt of cancer therapy, and other important factors such as time to treatment," he said by email. "However, cancer care is complex, and it will be important to determine if there were other unmeasured provider- and healthcare system-related factors that may account for the findings, such as polypharmacy, differences in administration of targeted therapies, decreased dosing of therapy in people with HIV, and importantly, lack of access to clinical trials."
"The study design did not allow for evaluation of immune status (i.e., CD4 count)," he noted. "There is a broad spectrum of immune suppression among people living with HIV that is related to how soon people start HIV therapy. The findings may not be generalizable to people who start HIV therapy early and have a normal CD4 count."
"Why do women with HIV and stage 3 breast cancer relapse sooner?" he continued. "Is this due to treatment-related factors, distribution of breast cancer biology (i.e., more triple negative breast cancer), or are there previously unrecognized factors related to underlying HIV or HIV-related immune dysfunction?"
For oncologists, "it is important to make sure that the treatment plan includes an evaluation of appropriate antiretroviral therapy," he said. "If there are concerns about possible interactions between cancer therapies and HIV therapies, it can be helpful to include a pharmacologist. We should also seek out clinical trials for our patients who have exhausted standard options."
"Interestingly, the study did not find inferior outcomes for lung cancer, which is a cancer that is associated with HIV," he said. "This raises the possibility that HIV may affect cancer risk and cancer outcomes differently."
JAMA Oncol 2019.
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