Two Grants, Two Cancers, One Research Question
Researchers at the Keck School of Medicine of USC and the USC Norris Comprehensive Cancer Center have received two National Institutes of Health grants totaling $7.5 million to investigate whether PFAS exposure contributes to liver and endometrial cancer.
The announcement from Keck covers two R01 grants awarded within six months of each other. The first, $3.4 million over five years, was awarded in March to study PFAS as a potential risk factor for hepatocellular carcinoma. The second, $4.1 million over five years, came in June to fund what researchers believe is the largest prospective study to date on PFAS and endometrial cancer risk.
The framing deserves care. These grants ask a question, not findings that answer it. No result exists yet. Coverage suggesting that forever chemicals have been shown to cause these cancers would be running years ahead of the science, and the research team does not claim otherwise.
Principal investigator V. Wendy Setiawan, a professor of population and public health sciences and medicine, said the shared purpose across both projects is straightforward: "We want to understand how environmental exposures contribute to cancer development" before the disease occurs.
Blood Samples Collected Before Diagnosis
The methodological choice at the center of both studies sets them apart from most existing PFAS research.
Both will use pre-diagnostic blood samples, meaning blood banked before participants developed cancer. That design addresses a persistent weakness in environmental cancer epidemiology. When exposure is measured after a diagnosis, results can be distorted by how the disease itself alters the body, and by patients' recall of past exposures. Measuring a chemical in blood drawn years before illness reduces both problems.
The liver cancer study will draw on the Multiethnic Cohort Study, which has followed participants in Southern California and Hawaii for more than 25 years. It pairs that epidemiology with laboratory work exposing human liver spheroids, three-dimensional liver models grown from donor cells, to multiple PFAS compounds at varying doses meant to mimic real-world exposure combinations. Preliminary data behind both applications came through the Southern California Environmental Health Sciences Center and the USC Center for Translational Exposomics Research.
That pairing matters. Population data can show an association. Laboratory work can identify whether a plausible biological mechanism exists. Neither alone establishes causation, and together they get closer to it than either.
The endometrial cancer study will use pre-diagnostic samples from 600 women who later developed the disease and 1,200 matched controls, pooled from the Multiethnic Cohort Study and the Southern Community Cohort Study, which follows participants in the southeastern United States.
Neighborhood and Food Access Enter the Analysis
The endometrial study includes a design element that connects environmental chemistry to household circumstance.
Researchers will analyze how neighborhood, income, and food access interact with PFAS exposure to influence risk. One hypothesis they describe directly: women living in food deserts, meaning communities with limited access to fresh food, may rely more on fast food whose packaging contains PFAS, compounding their exposure.
If that pattern holds, it would mean PFAS exposure is not distributed evenly across the population, and that where a person lives shapes it. That is a testable claim rather than an assumption, and the study is designed to test it.
The underlying context is not in dispute. PFAS are used in nonstick cookware, stain-resistant fabrics, food packaging, and many other products. Because they break down very slowly, they accumulate in the environment and in the body. They are detected in the blood of nearly all U.S. residents and have been found in roughly half of the country's public drinking water supplies. Growing evidence links PFAS exposure to kidney disease, liver damage and several cancers, though the biological mechanisms behind many of those associations remain poorly understood. Filling that gap is a stated purpose of both projects, and a USC center focused on PFAS assessment and remediation is part of the broader effort.
Endometrial cancer is the most common gynecologic cancer in the United States, with rates rising for at least a decade and diagnoses occurring at younger ages. Hepatocellular carcinoma accounts for roughly 80 percent of liver cancers and carries a five year survival rate of 22 percent, and its causes have been shifting from hepatitis infection toward metabolic conditions including obesity and fatty liver disease.
Findings Are Years Away From Existing
Nobody should change anything about their health care because these grants were awarded, and no clinician would order a PFAS screening test for a symptom-free person.
People who want to reduce exposure have limited but real options. Households can check whether their public water system has published PFAS testing results, which many now do under federal reporting requirements, and can look into filtration certified for PFAS reduction if levels are a concern. Reducing reliance on grease-resistant food packaging is another commonly suggested step. None of these is a proven cancer prevention measure, and framing them that way would overstate what is known.
Anyone with symptoms of either cancer should see a clinician regardless of exposure history. For endometrial cancer, abnormal vaginal bleeding, particularly any bleeding after menopause, is the symptom that warrants prompt evaluation. Liver cancer often produces few early symptoms, which is why people with cirrhosis or chronic hepatitis are placed in surveillance programs.
Both grants run five years. Results will not appear for years, and the studies may find no association, a weak one, or a meaningful one. The stated goal for the liver project is to produce research that can inform policies to minimize exposure and help people already exposed. Whether it gets there is an open question. MedicalDaily will report when either team publishes findings.
Key Questions Answered
What was announced? Two NIH R01 grants totaling $7.5 million to USC researchers to study whether PFAS exposure contributes to liver cancer and endometrial cancer.
Do the grants prove PFAS cause these cancers? No. These fund studies asking the question. No results exist yet, and the studies may find no association.
Why use blood samples collected before diagnosis? Measuring exposure before disease develops avoids distortion from the illness itself and from patients' recall of past exposures.
How large are the studies? The endometrial study will use samples from 600 women who developed the cancer and 1,200 matched controls. The liver study draws on a cohort followed for more than 25 years.
How common is PFAS exposure? PFAS are detected in the blood of nearly all U.S. residents and have been found in roughly half of the country's public drinking water supplies.
Is there a test for PFAS exposure? No clinician would order one for a symptom-free person. No established clinical action is based on such a result.
When will results be available? Both grants run for five years, so findings are years away.
