Knowing whether or not breast cancer is likely to spread could change the way doctors treat the disease.
The knowledge could also help some people avoid unnecessary treatment.
Breast cancer becomes life threatening when cancer cells break off from the primary tumor. Cancer cells can travel to any part of the body once they enter the bloodstream.
Researchers at Albert Einstein Cancer Center and Montefiore Einstein Center for Cancer Care believe they discovered the “doorway” that allows breast cancer cells to enter the bloodstream.
The researcher carried out the study on a mouse model of human breast cancer and mice implanted with human breast tissue. They also used real-time, high resolution imaging.
In previous studies, researchers found that breast cancer spreads when three specific cells come into direct contact with each other. One is a type of cell that lines the blood vessels, another is a type of immune cell found near blood vessels, and the third is a tumor cell that creates a high level of the protein that encourages cell to spread.
The tumor’s microenvironment of metastasis is the place where these three cells get together. This is the doorway researchers that that cancer cells use to enter the blood vessels.
Tumors with a high TMEM score are more likely to spread than tumors with lower scores.
TMEM macrophage releases vascular endothelial growth factor. This protein increases blood vessel permeability. It’s a short-term effect, but it gives cancer cells ample opportunity to get through.
Researchers also discovered that transient blood vessels permeability and tumor cell entry into the blood stream happen at the same time. This is a process that only occurs at TMEM sites.
According to the American Cancer Society, this year there will be about 231,840 new cases and invasive breast cancer in women. An estimated 40,290 women will succumb to it, mostly from metastatic breast cancer.
This study opens the door to the development of new anti-metastasis therapies.
