Dr. Simon on Genomic Assays for Patients With Breast Cancer

Michael Simon, MD, MPH, medical oncologist, Karmanos Cancer Institute, discusses genomic assays for patients with breast cancer.

MammaPrint and Oncotype refer to genetic testing of a patient’s tumor to predict the risk of relapse. Oncotype has been clinically validated for use in women with early-stage breast cancer to determine whether they are candidates for chemotherapy and hormone therapy, or hormone therapy alone. The benefit, Simon says, is that clinicians can forego chemotherapy in many patients.

Data from the upcoming Annual ASCO Meeting may support its use in women with lymph node-positive cancer as well. It is important for healthcare providers and patients to understand that this is tumor genetic testing, whereas germline genetic testing refers to genes in every cell. Germline mutations can be passed on to offspring or inherited by siblings, says Simon. Right now, the optimal time for Oncotype or MammaPrint is after diagnosis of early-stage hormone-sensitive breast cancer, says Simon.