There are hundreds of published scientific research papers covering the topic of PFAS and cancer. In this article, we take a closer look at the current state of PFAS and cancer research. The bottom line is that the evidence is clear. High and consistent exposure to PFAS increases the risk of developing cancer. Read on to learn more about what research says about cancer risk due to PFAS exposure.
Background on PFAS and cancer research
The gold standard for human scientific research is the randomized controlled trial. For many health research topics like PFAS exposure, it is difficult to run randomized controlled trials. This is because the long-term health impact of PFAS chemicals may take months or years to develop. It’s impractical for research subjects to remain in controlled trials for extended periods. It’s also nearly impossible to fund such research given costs that could run tens or hundreds of millions of dollars.
There are alternatives to randomized controlled trials to study the impact that PFAS has on cancer risk. Researchers are able to study PFAS exposure risks through what are called epidemiological studies. These studies typically look at populations to understand the distribution of diseases and the potential causes. Other types of PFAS studies include case-control studies, observational studies, and retrospective studies. Scientists can also study the effects of PFAS in human cell lines to see how cells respond to PFAS exposure. Finally, researchers also look at animal models to better understand what PFAS can do to organ systems or whole animals. Examples include studies done using zebrafish or nematode worms. The scientific field uses all of these research studies to draw conclusions about the potential role of PFAS in cancer.
Cohort analysis shows correlations between PFAS and certain cancers
There have been dozens of epidemiological studies that have tried to better understand the association between PFAS exposure and cancer. A review study published in 2023 looked at 15 different PFAS studies and conducted a meta analysis of all the studies. (A meta analysis combines results from different studies and applies statistical methods to draw conclusions from the combined research data). Eleven of the studies in this meta analysis looked at kidney cancer, and the combined data showed an association between higher PFAS exposure and kidney cancer. There was a 1.7 times higher relative risk of kidney cancer among those with high PFAS exposures. Similarly, eight studies looked at testicular cancer using the same methods. It found a 2.2 times higher relative risk of testicular cancer in people with high PFAS exposures. In other words, high PFAS exposure seems to cause 2.2 times as many cases of testicular cancer as would be normally expected. You can read more about how to interpret relative risk. What’s quite interesting is that there was no correlation between PFAS and liver cancer across the 15 different studies. This is consistent with other studies in that PFAS has been shown to increase the risk of certain cancers, but not all cancers.
Note that there wasn’t a uniform definition for “high” exposure across all the studies. Generally, high exposures tended to mean having greater PFAS than the average person. High exposure was usually due to occupational PFAS exposure or from drinking PFAS-contaminated water over months or years.
PFAS is associated with specific cancers in women
The National Health and Nutrition Examination Survey (NHANES) is a wide-ranging health study conducted by the CDC. The study includes direct measurement and tracking of certain PFAS compounds over many years. It provides a rich healthcare and lifestyle dataset about Americans that is useful for all sorts of research.
An in-depth research project using NHANES data was conducted by a research collaboration across top universities. In this research, the teams were looking to assess correlations between certain cancers and PFAS levels. There were 76,454 people who had health outcomes data (such as whether they had certain types of cancer). Out of these people, 16,696 had PFAS blood tests conducted. Using this data, the researchers found an association between skin cancer and PFAS levels in women. Women with skin cancer were 1.72 to 2.07 times more likely to have high PFDE, PFNA, and PFUA levels than women without skin cancer. A similar finding occurred for uterine cancer. Women with uterine cancer were 1.55 times more likely to have high PFNA levels than women without uterine cancer. (PFDE, PFNA, and PFUA are specific types of PFAS chemicals).
There have been studies on the potential links between PFAS exposure and breast or ovarian cancer as well. While the evidence is mounting, additional studies are needed to better understand the link between PFAS and cancer in women.
Early detection and monitoring of PFAS exposure could help
The National Academies of the Sciences, Engineering, and Medicine published a consensus study report providing guidance on PFAS testing and clinical follow-up. This 280 page document provides comprehensive details on PFAS. It includes the recommendation to test for PFAS among higher risk individuals. Higher risk may be due to occupational exposure to PFAS or high levels of PFAS in drinking water and from products used in daily living. Key benefits of testing as highlighted in the consensus report include:
- Increased awareness of exposure so that exposure can be reduced
- Empowerment of communities to respond to contamination
- Relief from the stress of not knowing one’s exposure level
- Identification of the potential risk for health conditions associated with PFAS exposure to inform subsequent preventive care
- Help in monitoring whether efforts to reduce exposure are working through the conduct of baseline and follow-up tests.
Relentless Health has developed an at-home PFAS test to help anyone who’s concerned about PFAS exposure and cancer risk. The PFAS test can help provide all of the above benefits noted in the consensus study.
