Katherine McGlynn

Ph.D.

National Cancer Institute

Senior Investigator

PLCO (Learn more about this study)

PLCO-554

Jan 27, 2020

Dietary fiber, whole grains and risk of hepatocellular carcinoma

Primary liver cancer, of which hepatocellular carcinoma (HCC) is the dominant histologic type, is the 6th most commonly occurring cancer in the world and is tied with stomach cancer as the 3rd greatest cause of cancer mortality. While a number of major risk factors are known, such as hepatitis B virus, hepatitis C virus, excessive alcohol intake, consumption of foods contaminated with aflatoxin, some rare genetic disorders, obesity, diabetes, and non-alcoholic fatty liver disease (NAFLD), approximately 40% of HCC in the U.S. remains unexplained. Diet has long been thought to play a role in HCC, but the identification of precise dietary constituents has lagged behind the dietary study of other cancers. One dietary constituent that may play a role is dietary fiber. Dietary fiber, and in particular, cereal fiber, has been inversely associated with obesity, diabetes and NAFLD, all of which are risk factors for HCC. In addition, fiber has been demonstrated to improve insulin sensitivity and decrease systemic inflammation. In animal models, fiber has also been reported to improve the integrity of the gut membrane and favorably alter gut microbiome composition, suggesting that dietary fiber may be inversely associated with the development of HCC. A recent murine study reported, however, that insoluble fiber, increased the risk of liver cancer, rather than decreasing it. Two epidemiologic studies, however, reported that fiber, in particular cereal fiber, and whole grain consumption were inversely associated with HCC. As a result, we seek to follow examine whether dietary fiber, both soluble and insoluble, and whole grain intake are associated with development of HCC in the PLCO study population.