Early breast cancer cells multiply and grow rapidly under compression within the body and continue multiplying even when the pressure is relieved, researchers at the University of Adelaide have found.
The breakthrough could lead to new ways to diagnose breast cancer, which killed more than 3,000 women in Australia last year, and predict those at greater risk.
Breast cancer cells undergo large amounts of pressure as they develop in the body said Dr Sarah Boyle, co-lead author of the study.
“Something that’s very prevalent in breast cancer cells that you don’t see in a lot of other cancers is the fact that they’re growing in a very, very small space,” she told Central News.
“The mammary duct is really tiny, and this itself is exerting a particular pressure on the cells.”
It can potentially be used to predict patients that may be at greater risk of developing worse disease, or having their breast cancer recur, or spread to a secondary site.
Boyle, who is a research fellow at the Centre for Cancer Biology, leads a team that focuses on understanding the physical properties of malignant tumors.
The researchers also looked at how changes in breast tissue throughout a person’s life could impact the growth of early cancer cells already present in the body.
“There’s a lot of remodelling that happens in the breast during puberty. When a woman gets pregnant, there’s another lot of remodelling, and obviously when she’s lactating,” said Dr Boyle.
“In terms of that remodelling, [we asked] how can different changes, and different pressures cause existing cancer cells to grow?
“That’s where the initial curiosity came from and why we wanted to study this.”
Breast cancer is the most commonly diagnosed cancer among women in Australia, with over 20,000 diagnosed each year.
According to the Australian Institute of Health and Welfare, it accounts for 27 per cent of estimated cancer diagnoses in women.
In the laboratory, researchers used a compression machine to squeeze breast cancer cells for 30 minutes, simulating the process inside the body.
They found that due to the presence of a protein called PIEZO1, the compression caused a channel in the surface of the cancer cells to open, allowing calcium ions to flow in. This activated a signalling pathway that triggered the cancer cells to grow.
“It’s what they call an ion channel,” says co-lead author Professor Michael Samuel, the head of the Tumour Microenvironment Laboratory at the Centre for Cancer Biology.
“It’s essentially a little hole in the cell wall that very selectively allows things to enter and leave, and this particular ion channel is activated by force.
“So when cells experience compressive stress, these ion channels appear to open, which allows calcium ions to go from outside the cell to inside the cell, and this activates the cell communication signalling pathways.”
Dr Boyle said the compression was not caused by external factors.
“We don’t believe that compression coming from an external source, such as mammograms, or wearing restrictive clothing, or a physical impact, like getting hit, would do the same thing,” she said.
“The level of force that we are applying is applied directly to the cells, so it’s a cellular level force.”
What does it mean?
The findings could potentially be used to predict patients who are at greater risk of developing worse disease.
“Some women may be more susceptible to cancers initiating in their bodies because they may express high levels of PIEZO1,” said Samuel.
“We think that would be a very useful screening tool, maybe alongside mammograms.”
The researchers also found patients with high levels of PIEZO1 were often negatively impacted as a result.
“We can take archived [patient] samples and assess their levels of PIEZO1, and we have been able to correlate that with a worse prognosis for patients,” said Boyle.
“So, it can potentially be used to predict patients that may be at greater risk of developing worse disease, or having their breast cancer recur, or spread to a secondary site.”
While survival rates for breast cancer are high, an estimated 3,353 people lost their lives to the disease in 2025.
“What kills most women that have breast cancer is metastasis, when the cancer spreads to other parts of the body, and it tends to do that to the bone, the liver, the lung or the brain,” said Samuel.
“Once it’s escaped and gone further, it’s really difficult to treat.”
What about other cancers?
According to the researchers, other cancers could also experience the same effects of compression, causing them to grow.
“Most cancers that people get, epithelial cancers: breast cancer, skin cancer, prostate cancer, colon cancer, and bowel cancer… they’re very susceptible, and they happen to be in this particular kind of environment where they’re likely to experience compression when they’re growing,” said Samuel.
“This seems to be a phenomenon that’s likely to be a player in a few different types of cancer.”
What’s next?
The researchers hope it will lead to new ways to diagnose and treat breast cancer.
“We think that this could be a potential mechanotherapy target,” said Boyle.
Trish Fuss was diagnosed with breast cancer at 46. Photo: The Centre for Cancer Biology
“We know about chemotherapy, we know about radiotherapy, and immunotherapy. Mechanotherapy is taking what we know about pathways that are induced by mechanical stimulus, such as compression, and designing therapies against those.
“We need to be very careful in that context, because a lot of these pathways are involved in normal functioning, so you have to be able to tease out what parts are being activated in cancers, and how you can specifically target them.”
Trish Fuss, a consumer advocate for the Centre of Cancer Biology and a survivor of breast cancer, said: “These studies give me so much hope for those who will be diagnosed with breast cancer in the future.
“My hopes are that everyone who is diagnosed [with breast cancer] will be a survivor. It might mean they’re on a long-term treatment plan, but if it means more time with family, that’s a great outcome,” said Fuss.
“Research is giving us the hope for better treatment options.”
Main image of Dr Sarah Boyle and Professor Michael Samuel courtesy of the University of Adelaide.
