Does it surprise you to learn that HIV-positive patients with cancer have worse survival rates compared to HIV-negative patients with cancer?

If you are not a doctor, you may believe this is simply to be expected as someone with two diagnoses is fighting a double and not just a single battle. Yet, a new study suggests the reasons behind this discrepancy in survival rates may be slightly more complicated. HIV-infected patients are less likely to receive treatment for some cancers than uninfected patients — in some cases, they are two to four times more likely to go untreated for cancer — and this may affect whether or not they live, the researchers suggest. "As cancer becomes an increasingly common cause of death in the HIV population, the issue of cancer treatment in the HIV-infected cancer population will grow in importance," said Dr. Gita Suneja, assistant professor of Radiation Oncology at the University of Pennsylvania and lead author of the study.

Early vs. Later Years of an Epidemic

For those who remember the years when a diagnosis of HIV/AIDS was an imminent death sentence, it is quite remarkable to read today how HIV-infected people now enjoy the same life expectancy as uninfected people. This newfound longevity among HIV patients, though, does not hold up when cancer enters the mix. Health outcomes among HIV-positive and HIV-negative cancer patients are simply not on par. To understand why this inconsistency exists, researchers used data from Connecticut, Michigan, and Texas to find adults diagnosed with non-Hodgkin’s lymphoma, Hodgkin’s lymphoma, or cervical, lung, anal, prostate, colorectal, or breast cancers between the years 1996 and 2010. Next, they ascertained HIV status and examined cancer treatment strategies for all the patients. Altogether the researchers evaluated a total of 1,087,648 patients diagnosed with cancer and 3,045 patients diagnosed with both HIV and cancer.

The researchers discovered striking treatment trends. A significantly higher proportion of HIV-infected individuals — almost twice as many — did not receive cancer treatment for diffuse large B-cell lymphoma (DLBCL), lung cancer, Hodgkin’s lymphoma, prostate cancer, and colorectal cancer. Patients infected with HIV were also less likely to receive standard treatment for local-stage DLBCL, non–small-cell lung cancer, and colon cancer. Overall, HIV-infected patients diagnosed with early-stage cancers were two to four times more likely to go untreated or receive inappropriate treatment for that disease compared to the uninfected patients.

In particular, HIV-infected individuals least likely to receive proper cancer treatment included those with low T-cell counts (suggesting a compromised immune system), males who had acquired HIV due to injection drug use, those between the ages of 45 and 64, African-Americans, and those with distant or unknown cancer stage. "In my clinical experience, I have seen uncertainty surrounding treatment of HIV-infected cancer patients," Suneja said. She explained how historically, patients with HIV have been excluded from clinical trials, since early HIV patients experienced worse toxicity levels and side effects when undergoing chemotherapy. Yet, because HIV patients never participated in drug trials, oncologists don't really know which treatments are safe and effective for them. "Many oncologists rely on guidelines … for treatment decision making,” she said, “and in the absence of guidance, they may elect not to treat HIV-infected cancer patients due to concerns about adverse side effects or poor survival.”

To close the gap among HIV positive and HIV negative patients, Suneja and her co-authors suggest clinical trials for cancer drugs should enroll HIV-infected patients and once the appropriate data is collected, oncology guidelines should include recommendations for HIV-infected patients.

Source: Suneja G, Shiels MS, Angulo R, et al. Cancer Treatment Disparities in HIV-Infected Individuals in the United States. Journal of Clinical Oncology. 2014.