Common ‘forever chemicals’ lurking in tap water and hundreds of every day products could cause cancer cells to quickly spread inside the body, making the disease harder to treat, a new study suggests.
Numerous studies have shown per- and polyfluoroalkyl substances (PFAS) are associated with multiple cancers, but now researchers have discovered the substances could also be associated with the spread of the disease.
A study done by Yale researchers found colon cancer cells exposed to PFAS showed signs of metastasis — cancer migrating to different parts of the body.
This raised concerns because as cancer spreads, it becomes harder to treat.
Nearly every person in the US — 97 percent — has detectable levels of PFAS chemicals in their blood, studies have shown.
The chemicals are nearly ubiquitous in the environment because it is almost impossible to break them down, deeming them ‘forever chemicals.’
They are used in products for their anti-stick and anti-stain properties, especially in kitchen cookware and fabrics, but industries are now moving away from them because of their detrimental impacts.
Researchers said the cancer cells showed signs of metastasis — or attempts to migrate to new areas of the body — when exposed to PFAS levels like those in the blood of firefighters (stock image)
Studies have shown exposure to the substances — particularly in high levels — raises the risk of cancer because the chemicals interfere with cell metabolism — or the chemical reactions carried out by cells to keep them alive and to help them divide into new cells.
PFAS has previously been linked to kidney cancer, prostate cancer and breast cancer, among others.
Along with being associated with cancer, the Yale paper, published this month in the journal Environmental Science and Technology, is the first to show they might also cause cancer to spread faster — in particular, colon cancer.
America is in the grips of a rise in colon cancer cases among young adults.
Nearly double the number of people younger than 55 years old are being diagnosed with the cancer now compared to a decade ago — at a rate of 60 cases per 100,000 people in the age group annually.
For the study, researchers used two types of colon cancer cells — a ‘wild type’ and a type with a KRAS mutation.
KRAS is a gene belonging to a group of genes called oncogenes, which have the potential to turn into cancerous tumors.
Approximately 30 to 50 percent of colorectal tumors are known to have a mutated KRAS gene.
However, some people are diagnosed with KRAS wild-type colon cancer, meaning there is no KRAS mutation in a person’s cancer.
Colon cancers with the KRAS mutation are more deadly because a mutation to this gene promotes cancer metastasis, or the spread of cancer to other parts of the body where new tumors form.
Researchers experimented with two types of PFAS — 2μM, or micrometers, long — and 10μM long — a level often observed in firefighters.
Firefighters have higher PFAS levels in their blood because they are regularly exposed to the chemicals via the foam they use.
And studies show firefighters also have a 21 percent higher risk of colon cancer.
For one part of the research, both types of cells were formed into spherical clumps, placed in petri dishes and exposed to PFAS chemicals for seven days.
Results showed the colon cancer cells showed signs of spreading when exposed to PFAS at 10um.
PFAS is a common contaminant in many household items from cookware to hamburger wrappers. It can remain in the environment as well as human tissue for years, even decades, before being cleared out
Dr Caroline Johnson, an epidemiologist at Yale who was involved in the research, said: ‘It doesn’t prove it’s metastasis, but they have increased motility, which is a feature of metastasis.’
The scientists said PFAS may cause cancer cells to spread because it interferes with their metabolism, or the chemical processes keeping them alive — which could accelerate their growth and promote them spreading to new areas in the body.
The scientists said they did not see unusual growth in the cells that were exposed to PFAS that is 2um long, which experts say is less likely to disrupt cells.
The study also included a second test where colon cancer cells were grown in a flat layer inside a petri dish.
Scientists then created a line down the middle of the layer to create two separate sides. The cells were exposed to 10um PFAS for seven days.
This also showed under firefighter-levels of PFAS the separated colon cancer cells started to grow back together, which the scientists said also indicated metastasis.
Dr Johnson added: ‘Many in vitro studies can’t be translated into humans.
‘But I think understanding first the mechanisms of how they can actually affect cancer cell growth is important.’
The scientists said they now plan to test the colon cancer cells by exposing them to lower concentrations of PFAS to understand whether this had the same effect.
Written by Luke Andrews for The Daily Mail ~ December 18, 2023