Despite known links between cancer and the virus that causes AIDS, less than half of cancer survivors in the U.S. younger than 65 have been tested for HIV, a first-ever government study finds.
Overall, only 41 percent of cancer patients surveyed reported having blood or saliva tests to tell whether they were infected with the human immunodeficiency virus, or HIV, a factor that could affect everything from the treatment they receive to their risk factors for additional disease — and death.
That means about 60 percent had never been tested at all.
"I expected to see more, a higher percentage tested," said Dr. Jun Li, a CDC epidemiologist and lead author of a study published Thursday in the journal Preventing Chronic Disease.
Awareness of HIV status is vital at the time of cancer diagnosis or recurrence to avoid treatment-related complications, including drug interactions and the potentially damagiing effects of chemotherapy on the CD4 cell count and HIV viral load, he added.
Li and his colleagues reviewed data from the 2009 Behavioral Risk Factor Surveillance System, or BRFSS, an ongoing CDC telephone survey used to gauge broad public health behaviors. The analysis included data from nearly 25,000 U.S. cancer survivors aged 18 to 64 who provided information about their HIV testing histories.
Overall, cancer survivors in that age group were nearly as likely as anyone else in the U.S. to have been tested for HIV. CDC figures showed that about 45 percent of American adults in the general population had been tested for HIV as of 2010, an increase from 36.6 percent a decade earlier.
But for people with cancer, the stakes are higher if they don’t know their HIV status. People with HIV are several thousand times more likely to be infected with Kaposi sarcoma, a debilitating skin cancer. They’re 70 times more likely to be diagnosed with non-Hodgkin lymphoma — and women are at least five times more likely to be diagnosed with cervical cancer, according to the National Cancer Institute.
In addition, people with HIV are also at higher risk of anal, liver and lung cancers and Hodgkin lymphoma.
Clearly, knowing HIV status is vital to effective cancer treatment, said Dr. Polly Newcomb, a cancer epidemiologist with Fred Hutchinson Cancer Research Center.
“I would say it might be appropriate for all cancer survivors to ask about whether they’ve been tested for HIV,” she said. “There are 14 million people living with cancer in the U.S. today. Those people, particularly those under the age of 65, should have had a recent HIV test and communicated that with their caregiver.”
Li said he was surprised to find that more cancer survivors weren't tested — and that their health care providers didn't insist on it.
Every year, some 50,000 Americans are newly diagnosed with HIV, according to the CDC. More than 1.1 million are living with HIV infection in the U.S. and almost 16 percent — nearly 1 in 6 — are unaware of their infection.
There are several possible reasons that people in general — and cancer survivors in particular — don’t get HIV tests, despite nearly a decade of CDC recommendations calling for screening in Americans ages 13 to 64.
Part of it may be the fear and stigma that still surround an HIV diagnosis, the study suggested. Part of it may be doctors’ reluctance to order the tests or patient worries about extra cost or whether the exam is covered by health insurance. Requiring written consent for HIV testing of non-pregnant adults may be another barrier.
Still, some places in the U.S. are doing better than others. The rate of HIV testing among cancer survivors ranged from a high of 68.3 percent in Washington, D.C., to a low of 24.1 percent in Nebraska. In Washington state, 44.3 percent of cancer survivors reported they’d had HIV tests, the study found.
Patients most likely to report HIV testing included those who were younger, black or Hispanic, single, not disabled and concerned about medical costs.
The new study, the first to quantify HIV testing among cancer patients, may be useful as a baseline for future studies, Li said. Boosting the rates of HIV testing among people with cancer could improve treatment and prognosis for patients battling two devastating diagnoses at the same time.
"Cancer survivors are such a vulnerable, high-risk population," Li said. "They should know their HIV status."
JoNel Aleccia is a staff writer at Fred Hutchinson Cancer Research Center. From 2008 to 2014, she was a national health reporter for NBC News and msnbc.com. Before that she was a reporter, editor and columnist for more than two decades at newspapers in the Northwest. Reach her at email@example.com.