More than a quarter of HIV+ patients are also infected with the Hepatitis C virus (HCV), which may complicate treatment and care decisions after a cancer diagnosis. The specifics of those complications haven't been well-researched in the past. Results from a new Fox Chase Cancer Center study on this patient population may start filling in that gap.
Fox Chase Hematologist and Medical Oncologist Stefan K. Barta, MD, MS, MRCP – who led the study – analyzed data from HIV+ patients diagnosed with lymphoma, collected over 17 years, to better understand how HCV infection influences survival outcomes. Dr. Barta's collaborators will present the group's findings at the 50th Annual Meeting of the American Society of Clinical Oncology.
Reactivation of HCV, in which the virus is detectable but not necessarily causing symptoms, is common in HIV+ patients. Notably, Dr. Barta and his team found that reactivation of HCV did not appear to worsen survival outcomes for lymphoma patients who also had HIV.
"Many patients do experience some reactivation of the Hepatitis C virus, but in most patients it seems to be self-limited and does not affect outcomes for cancer treatment," said Dr. Barta.
He noted that treating lymphoma patients co-infected with HIV and HCV requires caution and care. HIV more than triples the risk of liver failure in individuals also infected with HCV, according to the Centers for Disease Control and Prevention. And among cancer patients, HIV+ patients infected with HCV can fall into a feedback loop that may lessen the effectiveness of treatment.
"Patients undergoing chemotherapy can experience reactivation of the Herpes C virus, which in turn can lead to liver failure," said Dr. Barta. "This means we have to dose-reduce chemotherapy, which could negatively affect outcomes."
In addition, HIV+ patients often take a host of other medications, including antiretrovirals, which makes them especially vulnerable to side effects like toxicity. However, Dr. Barta said the new study suggests the potential risks shouldn't deter oncologists from treating these patients with chemotherapy.
"People should not be scared of treating patients with HIV and HCV aggressively," said Dr. Barta. "At the same time, we have to be careful and cautious to monitor those patients because reactivation does occur and could potentially lead to severe liver failures."
He and his colleagues analyzed the medical records of 190 HIV+ patients who had been diagnosed with lymphoma at the Albert Einstein Cancer Center in Bronx, New York, from 1997 to 2013. Patients with primary central nervous system lymphomas were excluded. The researchers found that 53 patients, or 28 percent, of eligible patients were also infected with HCV. The virus reactivated in 17 of those patients, or about one-third of the patient population infected with HCV, during treatment.
Patients infected with HCV had an overall survival of 59.7 months, compared to 88.6 months for patients with neither HCV nor Hepatitis B Virus (HBV). However, that survival advantage vanished when the researchers adjusted for variables including age, sex, race, CD4 count, presence of cirrhosis, type of lymphoma, and levels of LDH (lactate dehydrogenase, an enzyme). The multivariate analysis showed that co-infection with HCV was not associated with lower overall survival in lymphoma patients. At the same time, the researchers did find worse overall survival outcomes associated with low CD4 count (below 100 cells/cubic millimeter), a diagnosis of non-Hodgkin lymphoma, advanced stage disease, LDH levels over 190, or cirrhosis.
Dr. Barta said he hopes the new study opens cancer clinical trials to an understudied patient population. HIV+ patients with HCV are often excluded from cancer clinical trials because of concerns about liver failure and drug toxicity, arising from the interaction of retroviral medications with chemotherapy. Barta says he hopes the new findings, which suggest these patients can tolerate chemotherapy without adverse outcomes, will help reverse that trend.
"This is really important for a large proportion of patients," he said. "We want to assure researchers that these patients, as long as they have adequate liver function, should also be enrolled in clinical trials."