Hepatitis C associated with increased risk for various cancers in older patients

Hepatitis C virus infection was associated with an increased risk for cancers other than hepatocellular carcinoma among elderly patients, a registry-based case–control study found.

“Hepatitis C virus infection is the most common chronic blood-borne infection in the United States, and approximately 3 million individuals are infected with this virus,” Parag Mahale, MBBS, PhD, of the division of cancer epidemiology and genetics at the National Cancer Institute, and colleagues wrote, adding that HCV can lead to development of hepatocellular carcinoma. “Approximately 70% of HCV–infected individuals in the United States were born between 1945 and 1965, prompting the CDC to recommend a one-time screening for HCV in this birth cohort. As baby boomers age, HCV–associated cancers in the elderly population may become an important public health issue in the United States in the near future.”

The researchers used the SEER registry to gather data on 1,623,538 patients with first cancers from 1993 to 2011, and matched them with 200,000 cancer-free controls. Researchers used logistic regression to identify associations with HCV infection.

Prevalence of HCV was greater in cancer cases than in controls (0.7% vs. 0.5%), and HCV was associated with a variety of cancers, including cancers of the liver (adjusted OR = 31.5; 95% CI, 29-34.3), intrahepatic bile duct (adjusted OR = 3.4; 95% CI, 2.52-4.58), extrahepatic bile duct (adjusted OR = 1.90; 95% CI, 1.41-2.75), pancreas (adjusted OR = 1.23; 95% CI, 1.09-1.4) and anus (adjusted OR = 1.9; 95% CI, 1.42-2.73).

HCV also was associated with nonmelanoma epithelial skin cancer (adjusted OR = 1.53; 95% CI, 1.15-2.04), myelodysplastic syndrome (adjusted OR = 1.56; 95% CI, 1.33-1.83), diffuse large B-cell lymphoma (adjusted OR = 1.57; 95% CI, 1.34-1.84), Merkel cell carcinoma (adjusted OR = 1.92; 95% CI, 1.3-2.85) and appendageal skin cancer (adjusted OR = 2.02; 95% CI, 1.29-3.16).

Uterine cancer (adjusted OR = 0.64; 95% CI, 0.51-0.8) and prostate cancer (adjusted OR = 0.73; 95% CI, 0.66-0.82) were both inversely associated with HCV.

The associations remained after sensitivity analyses conducted among individuals without a documented history of alcohol abuse, cirrhosis, hepatitis B or HIV, and after adjustment for socioeconomic status.

“A better understanding of the overall aging process and its relation to cancer is needed,” Daneng Li, MD, assistant clinical professor of the department of medical oncology at City of Hope in California, and Arti Hurria, MD, director of City of Hope’s Cancer and Aging Research Program, wrote.

“The article by Mahale [and colleagues] in this issue of Cancer identifies HCV infection as a potential additional risk factor for the development of various cancers among older adults,” Hurria and Li wrote. “Their study is an important step toward raising awareness of the potential importance of HCV diagnosis and treatment among older adults.” – by Andy Polhamus