The connection between Hepatitis C virus (HCV) and certain cancers has been studied previously, with findings showing that HCV infection causes hepatocellular carcinoma, a type of liver cancer, and subtypes of non-Hodgkin lymphoma. In a paper published in Cancer, Dr. Jennifer Kramer and colleagues examine the link between HCV and other cancers within the U.S. elderly population.

Kramer, assistant professor of medicine – health sciences research at Baylor College of Medicine and the Michael E. DeBakey Veterans Affairs Medical Center, collaborated on a National Cancer Institute study that analyzed Surveillance, Epidemiology, and End Results (SEER)-Medicare data on adults 66 years of age and older. The study included 1,623,538 participants with first cancers identified in SEER registries who were enrolled as cases, and 200,000 randomly selected, cancer-free participants who served as controls.

“We found that HCV was more prevalent in the cases than in the controls, and that it was positively associated with multiple cancer types,” Kramer said. “This shows us that HCV is associated with an increased risk of cancers outside of hepatocellular carcinoma and supports a potential causative role of HCV in an expanded group of cancers.”

The cancers associated with HCV other than liver included cancers of the bile ducts, pancreas, anus, non-melanoma non-epithelial skin cancers, diffuse large B-cell lymphoma, and myelodysplastic syndrome.

The study was designed and funded by the National Cancer Institute and led by Dr. Parag Mahale, who conducted the research as part of his doctoral dissertation at The University of Texas Health Science Center in Houston.

According to Mahale, “Some of the associations with HCV that we observed may not reflect a causal relationship, but HCV is known to be an important cause of liver cancer. It is also plausible that the virus contributes to other cancers, such as bile duct cancer, lymphoma and perhaps myelodysplastic syndrome.”

The study notes that, although there is a high prevalence of HCV infection in baby boomers, less than 50 percent know about their infection, and fewer receive appropriate treatment. As the baby boomer generation ages, this rate is likely to continue to rise.

“As this population ages, it is important that elderly individuals previously infected with HCV understand their risk for liver disease and cancer down the road,” Kramer said. “When we know which patients are at a highest risk, we can better understand how to treat and manage these patients early on, through the use of direct-acting antivirals, for example.”

Other contributors to this work include Eric Engels with the National Cancer Institute, Harry Torres with MD Anderson Cancer Center, and Ruosha Li, Eric Brown and Lu-Yu Hwang with The University of Texas School of Public Health.