Researchers from the Institute of Cancer Research in London have developed a new genetic test for women with breast cancer. The test predicts how patients will respond to therapy even before it starts. To do this, a few drops of blood are enough.
The test looks for genetic variants that make the tumor resistant to certain drugs. In this way, doctors know in advance if it is worth going ahead with a certain type of treatment. Furthermore, it is useful in cases of chronic cancer. In some cases, in fact, cancer cells become resistant to certain drugs and therefore we must change strategy. In the future, such tests could help identify almost half of women at high risk of recurrence. Doctors will see in advance if the cancer has become resistant to drugs and the therapy must be changed.
To develop the test, the researchers examined the blood samples from 310 women. All women suffered from the most common form of breast cancer, all in an advanced stage. The patients were testing two drug therapies designed for tumors of this type. About 42% of them (131 women) showed genetic variants related to the risk of relapse. On average, women with these variants had a tumor return 3.9 months after the end of therapy.