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Exposure to chemicals used in nonstick cookware, cosmetics and clothes has been linked to the most common type of liver cancer, a new study shows.

New research from the University of Southern California’s Keck School of Medicine suggests exposure to high levels of a class of organic pollutants known as perfluorooctane sulfonic acid are associated with an increased risk for liver cancer, specifically nonviral hepatocellular carcinoma. This is the first proof-of-concept study that investigated the relationship between these chemicals and liver cancer in humans.

Headshot of Dr. Jennifer Permuth

Dr. Jennifer Permuth, cancer epidemiologist and vice chair of research in Gastrointestinal Oncology

Hepatocellular carcinoma (HCC) is the most common and deadly type of liver cancer.  While vaccination efforts and effective antiviral treatments have helped to decrease the incidence of hepatocellular carcinoma related to hepatitis B and C, the incidence of nonviral HCC is on the rise. Likely causes are increasing rates of nonalcoholic fatty liver disease, nonalcoholic steatohepatitis (an advanced form of nonalcoholic fatty liver disease), obesity and diabetes.

There is a critical need to identify modifiable risk factors for nonviral hepatocellular carcinoma to improve identification and surveillance of at-risk populations. This new research is a start.

“Experimental evidence supports the ability of these forever chemicals to have toxic effects on the liver and to disrupt metabolic processes, so there is biological rationale to explain the reported association. This study therefore attempts to pave the way for filling a key gap in our understanding of the consequences of being exposed to these chemicals,” said Dr. Jennifer Permuth, a cancer epidemiologist and vice chair of research in Gastrointestinal Oncology at Moffitt Cancer Center.

There are thousands of chemicals under the umbrella of per- and polyfluoroalkyl substances, or PFAS. These substances are often referred to as “forever chemicals” because they take a long time to break down in the environment and in our bodies. PFAS chemicals have been used in a variety of products since the 1940s. They are typically used to provide oil, water and heat resistance. However, over the past 20 years there has been increasing evidence that exposure to PFAS can contribute to numerous health issues.

For the liver cancer study, researchers analyzed pre-diagnostic blood taken from 50 individuals diagnosed with nonviral hepatocellular carcinoma and 50 healthy controls who did not have the disease. They measured levels of various types of PFAS in the participants’ blood and found that those with high levels were 4.5 times more likely to develop hepatocellular carcinoma than those with lower levels. While the results provide evidence of an association between PFAS exposure and hepatocellular carcinoma, Permuth and the authors of the study pointed out the research was based on a very small sample size.

“Larger studies are needed to confirm these findings,” she said. “Additionally, it is worth noting that the hepatocellular carcinoma cases in this study were more likely to be overweight or obese and to have diabetes than the controls. The association between PFOS exposure and hepatocellular carcinoma risk did not reach statistical significance when accounting for being overweight or obese. Because obesity and presence of diabetes can serve as risk factors for nonalcoholic fatty liver disease and hepatocellular carcinoma, future larger-scale studies of PFAS and HCC must consider such factors in their design and analysis.”

How to Limit Your PFAS Exposure

  • Check labels on stain and water repellent clothing to see if PFAS were used in manufacturing. This primarily pertains to shoes, raincoats, yoga pants and other accessories.
  • Check stain resistant furniture, carpets and mattress pads. Look for Scotchgard, Stainmaster or other treatments containing PFAS.
  • Be aware of the cooking pots and pans. The chemicals used in many nonstick pans such as Teflon can get into food. Consider brands such as GreenPan, which report to be free of PFAS and metals such as lead and cadmium.
  • PFAS are widely used to coat pizza boxes, fast food wrappers, microwave popcorn bags and other paper goods so that they are resistant to grease. Eating fast food less frequently and avoiding microwaving these products are another way to minimize exposure to chemicals in these paper goods.
  • PFAS have been found in drinking water. Some water filtration units have been reported to help remove PFAS using approaches that rely on reverse osmosis or charcoal filters.
  • Cosmetics and personal care products can contain PFAS. Closely read labels or check databases like Skin Deep®, which provides ingredient lists and safety ratings for thousands of cosmetics products.