Is protein responsible for breast cancer?

Some scientists have found a strong link between a certain protein to breast cancer.

According to a research conducted by the University of Montreal, a certain protein that, once deactivated, could prevent the development of metastases in an aggressive type of cancer, HER2-positive breast cancer.

The study was led by Jean-François Cote and team. One in eight women will be diagnosed with breast cancer in her lifetime and one in 30 is expected to die from it.

A cancerous tumour develops when cells proliferate at an abnormally high rate and agglomerate in healthy tissue. Some of these cells are even more cunning.

"Sometimes, cancer cells manage to leave the tumour to spread in the body, which complicates the evolution of the disease," said researcher Cote.

These cells move more easily than most of their peers. They detach from a tumour, enter the bloodstream and reach other organs, for example, the lungs, bones or the brain. Called 'metastatic cells,' they are more difficult to destroy as they spread to other parts of the body and are more resistant to current treatments; 90 percent of breast-cancer deaths are caused by metastases.

Hence, one priority in oncology is to prevent tumour cells from spreading because it has the potential of saving many lives.

The researchers have taken a step towards actually blocking metastases. In their study, the IRCM team demonstrated that a protein, AXL, influences the occurrence of metastasis in HER2-positive cancer, an aggressive type that accounts for 20 percent of breast cancers.

In HER2-positive breast cancers, cells with high levels of AXL are more likely to detach from tumours to form metastases.

In women with HER2-positive cancer, it was found that the less AXL is present, the better the survival rate. Previously, researchers had linked the AXL protein to another type of cancer, triple negative breast cancer, but no one had examined its presence in HER2-positive cancer before Cote and his team.

"Based on this discovery, a treatment targeting AXL could reduce the risk of metastasis," said Cote.

The findings are published in the journal Cell Reports.