Hepatitis C virus (HCV) infection may be linked to cancers other than hepatocellular carcinoma (HCC), such as bile duct cancers and diffuse large B-cell lymphoma (DLBCL), according to a study published in Cancer.
Chronic HCV infection is a known cause of HCC and B-cell non-Hodgkin lymphomas (NHLs), but epidemiologic data suggest that HCV may be associated with cancers involving the kidney, oropharynx, and bile duct. HCV antigens and RNA have been identified in some of these cancers, but the exact role of the virus in oncogenesis is unclear. Since the majority of patients with HCV infection were born in the “baby boomer” era, HCV-associated cancers may present a potential public health issue as the baby boomer population ages.
A team of researchers led by Parag Mahale, MBBS, PhD, from the National Cancer Institute, examined the relationship between HCV infection and cancers other than HCC using data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare registry.
Data from 1,623,538 patients with cancer and 200,000 cancer-free matched controls were included for analysis. Individuals in each cohort were 66 years of age or older.
Overall, patients with cancer were more likely to have HCV infection than controls (0.7% vs 0.5%; adjusted odds ratio [aOR], 1.32; P <.0001).
HCV infection correlated with an increased risk for multiple gastrointestinal cancers, including cancers of the liver (aOR, 31.5), pancreas (aOR, 1.23), intrahepatic bile duct (aOR, 3.40), and extrahepatic bile duct (aOR, 1.90).
Hematologic disorders and malignancies associated with HCV included myelodysplastic syndrome (aOR, 1.56) and DLBCL (aOR, 1.57).
HCV was also linked to nonmelanoma nonepithelial skin cancer (aOR, 1.53), including subtypes Merkel cell carcinoma and appendageal skin cancers.
These findings show that HCV infection is associated with cancers other than HCC and NHL in the elderly US population. “However, to determine whether HCV infection actually ‘causes’ these cancers, further studies are required,” Dr Mahale said in an interview with Infectious Disease Advisor. “HCV treatment is known to reduce the risk of hepatocellular carcinoma, but whether viral eradication reduces the risk of other cancers is not yet known.”
For the time being, Dr Mahale advises following guideline recommendations for HCV screening and treatment. “Clinicians should test baby boomers — those born between 1945 and 1965 — for HCV infection, according to the [Centers for Disease Control and Prevention] CDC guidelines and offer them treatment to eradicate the infection,” he said.
Mahale P, Torres HA, Kramer JR, et al. Hepatitis C virus infection and the risk of cancer among elderly US adults: A registry-based case-control study [published online January 24, 2017]. Cancer. doi:10.1002/cncr.30559