People with hepatitis C are two to five times more likely to develop certain head and neck cancers

Long associated with liver cancer and non-Hodgkin's lymphoma, a study from The University of Texas MD Anderson Cancer Center reveals for the first time that the hepatitis C virus (HCV) is associated with certain head and neck cancers. The findings, published in the Journal of the National Cancer Institute, could have significant implications for both the screening of those with the virus and the treatment of those with head and neck cancers.

Hepatitis C, the most common blood-borne infection in the U.S., is a virus that affects up to 1.5 percent of the population. It's estimated that as many as 3.9 million are chronically infected with the virus, according to the researchers.

In the last few years, new antiviral drugs have made it possible to cure more than 90 percent of the HCV population, says Harrys A. Torres, M.D., associate professor, Infectious Disease, Infection Control and Employee Health. The antivirals are oral medications taken once or twice daily with almost no side effects, he explains.

In 2009, MD Anderson opened what remains the only clinic of its kind at a comprehensive cancer center to address the unmet medical needs of its patients with HCV.

"Obviously, a hepatitis C infection could impact how patients respond to their cancer therapy. We also realized that many of our hepatitis patients were excluded from clinical trials. Now that many with hepatitis C can be cured, it is important that we first address and potentially cure the virus, so that they can have access to necessary cancer therapy."

When Torres started the clinic, he expected to see a number of patients with liver cancers and non-Hodgkin's lymphoma, as these have documented associations with HCV of 48-fold and two- to three-fold increased risk, respectively. Other recent studies have recognized HCV's increased association with additional cancers, says Torres, but there was no known association with a significant number of head and neck cancers.

"To our surprise, we saw a number of head and neck cancer patients who tested positive for the hepatitis C virus. With this observation we began to wonder if there was an undiscovered correlation between the two. Our findings tell us that the association between hepatitis C and oropharyngeal and nonoropharyngeal cancers is as high as its link to non-Hodgkin's lymphoma."

Oropharyngeal cancers occur in the oropharynx, or the middle part of the throat, including the back one-third of the tongue, the soft palate, tonsil, and side and back walls of the throat. Nonoropharyngeal cancers include those occurring in the oral cavity, nasal cavity and larynx.

For the retrospective, case-controlled study, the researchers identified 34,545 MD Anderson patients who were tested for HCV between 2004 and 2014. All patients were tested for HCV antibodies and viral RNA tests were used to confirm chronic infection, when available.