Chemotherapy, hormone therapy, radiation therapy, surgery… When you’re diagnosed with breast cancer, all of the treatment options can be daunting. But a new genetic test may soon make the decision a lot easier regarding chemotherapy.
Researchers from Queen Mary University in London used the multi-gene test EndoPredict to assess whether chemotherapy would be beneficial for women with the most common type of breast cancer (estrogen-receptor positive, HER2-negative), according to a study published in Breast Cancer Research and Treatment. Generally, doctors recommend chemo to women who have high risk for metastasis (when the cancer spreads).
Along with scientists from the Austrian Breast and Colorectal Group in Vienna and the Spanish Foundation Research Group in Breast Cancer in Madrid, researchers performed three large clinical trials with almost 4,000 women. The results were impressive: The women who were identified as high-risk by EndoPredict and received chemo in addition to hormone therapy had statistically better outcomes over 10 years than those who received hormone therapy without chemo.
A key benefit of this test is its ability to help women avoid the often severe mental and physical toll of chemotherapy. "Our data shows that using the EndoPredict test to assess the risk of metastasis can spare women unnecessary chemotherapy if the results show that a woman is at low risk of recurrence,” said lead study author Ivana Sestak, M.D., of Queen Mary University, in a press release.
Chemo isn’t recommended for every breast cancer patient, but sometimes it can be hard to tell whether it will be helpful. Typically doctors perform genetic tests on the patient and look at things like tumor size and grade to figure out the best course of treatment for patients with estrogen-receptor positive breast cancer, which affects 85% of women with the disease.
In cases when the typical methods to determine prognosis and treatment are inadequate, this new test can help provide answers, the researchers say. More research is required before the test becomes available publicly, but based on these study results, it may someday become an important treatment tool. The OncoType DX assay test adds to one that is already available to patients. The new genetic test does not help decide about hormone therapy, radiation, or surgery. Other prognostic multigene assays may be considered to help assess risk of recurrence but have not been validated to predict response to chemotherapy.