HCV Linked to Multiple Cancers Besides Liver Cancer.

Hepatitis C virus (HCV) infection has been established as a risk factor for hepatocellular carcinoma, the most common type of primary liver cancer. However, a study recently published in Cancer found that HCV infection is associated with a number of other cancers as well.

This was a case-control study using data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. 1.6 M cancer cases were matched to 200,000 cancer-free controls. HCV prevalence was higher in cases than controls (0.7% vs 0.5%). HCV was positively associated with cancers of the liver, intrahepatic bile duct, extrahepatic bile duct, pancreas, and anus; nonmelanoma nonepithelial skin cancer; myelodysplastic syndrome; and diffuse large B-cell lymphoma. Specific skin cancers associated with HCV were Merkel cell carcinoma and appendageal skin cancers. It was negatively associated with uterine cancer and prostate cancer.

However, it is thought that the association between HCV and anal cancer and nonepithelial skin cancers may be confounded by shared risk factors. A high prevalence of HCV infection is seen in men who have sex with men and injection drug users; both groups have a high prevalence of HIV infection, which is associated with increased risk of anal cancer. HIV infection is also associated with an increased risk of nonepithelial skin cancers.

The authors suggested that HCV was negatively correlated with uterine cancer because total abdominal hysterectomy is associated with a risk of hemorrhage requiring blood transfusion, and the blood supply was not screened for HCV before 1992. Therefore, the prevalence of HCV would be higher in patients with uterine cancer, who obviously did not previously undergo hysterectomy.

HCV is thought to be negatively associated with prostate cancer because of lower rates of screening for prostate cancer in HCV infected patients, who are often of lower socioeconomic status.

-Sally Tran

References:
Huseman A. "Study shows link between Hepatitis C virus, multiple cancers." Baylor College of Medicine News. 2017 Jan 26. https://www.bcm.edu/news/cancer/link-between-hepatitis-c-virus-cancers

Mahale P, Torres HA, Kramer JR, Hwang L, Li R, Brown EL, Engels EA. "Hepatitis C infection and the risk of cancer among elderly US adults: A registry-based case-control study." Cancer. 2017 Jan 24. doi: 10.1002/cncr.30559