A study entitled “Tumor Microenvironment of Metastasis and Risk of Distant Metastasis of Breast Cancer” has been published online in the Journal of the National Cancer Institute (JNCI). Led by researchers at the National Cancer Institute (NCI), the study provides insight into tests assessing metastatic risk in breast cancer. To measure the test’s effectiveness, the researchers used it on about 500 breast tumor specimens that had been collected over a 20-year period. The test proved more accurate in predicting the risk of distant tumor spread than a test closely resembling a leading breast cancer prognostic indicator on the market.
The JNCI paper observed that primary breast cancers metastasize when a specific trio of cells is present together in the same microanatomic site: an endothelial cell, a perivascular macrophage, and a tumor cell that produces high levels of Mena, a protein that enhances a cancer cell’s ability to spread. A site where these three cells touch is where tumor cells can enter blood vessels. That site is called a tumor microenvironment of metastasis, or TMEM.
TMEM testing was carried out on specimens from 259 women who later developed a distant metastasis (the cases) and on specimens from women who were alive and had not developed a distant metastasis (the controls).The TMEM test performed well at assessing metastatic risk for the study’s most populous cancer subgroup: women with estrogen receptor positive/HER2- disease.
“We’re pleased we found a strong and statistically significant association between TMEM score and risk of metastasis in the most common type of breast cancer,” says Thomas Rohan, MD, PhD. “This assay could eventually reduce overtreatment of early stage breast cancer, which remains a major problem despite extensive use of other prognostic assays,” adds study coauthor Joseph Sparano, MD. Learn more about TMEN and the Tumor Microenvironment initiative launched by the NCI in 2006.Read more