‘Forever’ chemical linked to liver cancer in first human study

There is growing evidence that regular exposure to man-made “permanent” chemicals used in a variety of household products is associated with increased rates of cancer.

A new study examining correlations between liver cancer and the presence of these chemicals in humans found that those with the highest exposure levels were 350% more likely to eventually develop the disease.

The term “forever” chemicals refers to over 4,700 available types of perfluoroalkyl and polyfluoroalkyl substances (PFAS) and is widely used in the manufacturing industry. in soil, drinking water and inside the body.

PFAS was first introduced in the 1930s as a revolutionary material used to make nonstick cookware (hello, Teflon) and quickly adapted to all kinds of products. and packaging — from construction materials cosmetic — because it is liquid and fire resistant, As pointed out by Centers for Disease Control and Prevention.

Such chemicals are incredibly useful, but have since been associated with the development of cancer and other diseases. in laboratory animals. Perfluorooctane sulfonic acid (PFOS) perfluorooctanoic acid (PFOA) was making consumers sick, so in 2006 the Environmental Protection Agency ordered eight multinational manufacturing companies represented by the United States to phase out the use of such chemicals. . Yet, as their nickname suggests, PFOS and PFOA Still detected in foreign products in groundwater and in people.

The current study, published in the JHEP report, is also the first to show a clear link between PFAS and non-viral hepatocellular carcinoma (the most common type of liver cancer) in humans.

“It builds on existing research, but goes a step further,” said Jesse Goodrich, a postdoctoral public health researcher at Keck College of Medicine. In a news release from the University of Southern California“Liver cancer is one of the most serious endpoints of liver disease, and this is the first human study to show that PFAS are associated with this disease.”

Showing a link between PFAS and cancer in humans has not been easy for scientists.

“One of the reasons there are so few studies in humans is that we need a good sample,” added Professor Veronica Wendy Setiawan of Keck College of Medicine. “If you’re looking at environmental exposures, you need samples from well before diagnosis because cancer takes time to develop,” she says.

To take this leap, researchers now have access to a multi-ethnic cohort studies database. This includes a study of cancer incidence among her more than 200,000 residents of Hawaii and Los Angeles, California, conducted by the University of Hawaii.

Their search narrowed down to 100 study participants, 50 of whom had liver cancer and 50 who did not, and sufficient blood and tissue samples were available for analysis. It was possible. Researchers were looking for traces of “permanent” chemicals in the bodies of a group of cancer patients before they got sick.

They reportedly found several types of PFAS among the participants, with PFOS being most prominent in the liver cancer group. In fact, their study revealed that people in the top 10% of PFOS exposures were 4.5 times more likely to develop hepatocellular carcinoma compared to those with the lowest exposures.

The clear link between PFAS and cancer in humans is important for further study of how these chemicals interfere with biological processes. According to current findings, USC scientists now believe that high levels of PFOS in some subjects impair the liver’s ability to metabolize glucose, bile acids, and branched-chain amino acids, resulting in a non-alcoholic We believe that unhealthy levels of fat have accumulated in known organs. Fatty liver disease — a risk factor for liver cancer.

As such, many scientists agree that it is no coincidence that the emergence and widespread use of “forever” chemicals has been correlated with an increase in liver disease, cancer, and liver disease. other diseases.

“Our study provides important insight into the long-term health effects of these chemicals on human health, particularly how they can impair normal liver function. We think so,” said study author Dr. Reda Chatsy. “This study fills an important gap in our understanding of the true consequences of exposure to these chemicals.”