A new test to determine whether breast cancer is likely to spread will allow patients to avoid unnecessarily invasive and potentially dangerous treatments.
It has been found that the cancer only spreads when three specific types of cells are in the same place at the same time.
The first is an endothelial cell, found in the lining of blood vessels; the second a perivascular macrophage, an immune cell found near blood vessels; and the third a tumour cell producing mena, an invasiveness-promoting protein.
Together they create a ‘tumour microenvironment of metastasis’ (TMEM), which the new test is designed to detect. A high density means that the tumour is either liable to metastasise or already has.
Previous reports have shown that the microenvironment contains regions of poor oxygenation and high acidity, with evidence pointing to a fundamental role for hypoxia in metastatic progression.
While increasing genomic instability and heterogeneity, it may also alter the expression of genes that could lead to changes in stress responses, anaerobic metabolism, angiogenesis, tissue remodelling and cell-to-cell contacts.