Washington: In a new study, scientists have found that it is the specific trio of cells that causes breast cancer to spread.
A study, led by researchers at the NCI-designated Albert Einstein Cancer Center and Montefiore Einstein Center for Cancer Care, combining tumor cells from patients with breast cancer with a laboratory model of blood vessel lining provides the most compelling evidence so far, and the findings could lead to better tests for predicting whether a woman's breast cancer will spread and to new anti-cancer therapies.
According to the National Cancer Institute, most breast cancer deaths occur because the cancer has spread, or metastasized, which means that cells in the primary tumor have invaded blood vessels and traveled via the bloodstream to form tumors elsewhere in the body.
In earlier studies involving animal models and human cancer cell lines, researchers found that breast cancer spreads when three specific cells are in direct contact: an endothelial cell (a type of cell that lines the blood vessels), a perivascular macrophage (a type of immune cell found near blood vessels), and a tumor cell that produces high levels of Mena, a protein that enhances a cancer cell's ability to spread. Where the 3 cells come in contact is where tumor cells can enter blood vessels-a site called a tumor microenvironment of metastasis, or TMEM. Tumors with high numbers of TMEM sites were more likely to metastasize than were tumors with lower TMEM scores. In addition, the researchers found that cancer tissues high in a form of Mena called MenaINV were especially likely to metastasize.
The present study combined results from those 40 patients plus an additional 60 patients. All 100 patients had been diagnosed with invasive ductal carcinoma and were being treated at MECCC. Invasive ductal carcinoma was the most common type of invasive breast cancer, accounting for 80 percent of cases.
Combining the results from all 100 patients showed that the findings were consistent across the three most common clinical subtypes of invasive ductal carcinoma.
Study leader Dr. Maja Oktay, noted that the outcome for patients with metastatic breast cancer had not improved in the past 30 years despite the development of targeted therapies.
The study is published online in Science Signaling.