Mammaprint genomic test (Agendia) spares Breast Cancer patients chemotherapy with no adverse effect on survival

Testing a Breast Cancer tumour for its genomic signature using the Mammaprint assay, from Agendia, can help identify which patients will need adjuvant systemic therapy (additional chemotherapy) after surgery, and spare its use in those for whom it is not necessary. The researchers studied 427 patients with early Breast Cancer in a study called RASTER. By looking for a particular selection of 70 genes in a tumour, the Mammaprint test can predict which patients are at low and which at high risk of metastasis, enabling doctors to select which patients to spare chemotherapy without adversely affecting their chances of disease-free survival. In the group classified as low risk by the Mammaprint test only 15% of the 219 patients received adjuvant chemotherapy as opposed to 81% (169/208) in the group classified as high risk by the Mammaprint test. The first group had a five-year distant disease-free survival (DDFS) rate of 96% compared with 90% in the high risk group. Many patients dread the idea of chemotherapy, and by avoiding it they can substantially reduce the stress involved in having cancer, as well as improve their overall quality of life, says lead researcher Dr. Sabine Linn, Associate Professor of Medical Oncology at The Netherlands Cancer Institute, Amsterdam. The researchers now intend to study two further genomic tests to see whether they can further refine prognosis in the same group of breast cancer patients. The data was presented to the 8th European Breast Cancer Conference.