beth - Myriad Genetics, Inc. (NASDAQ: MYGN), a leader in genetic testing and precision medicine, announced today Clinical Cancer Research, a journal of the American Association for Cancer Research, published a study 1 that shows the EndoPredict® breast cancer prognostic test significantly predicted distant recurrence in premenopausal women with ER+, HER2- early-stage breast cancer. This newly published study represents the first clinical validation of EndoPredict in a solely premenopausal population.

The study -- first presented in an abstract at the 2021 ASCO Annual Meeting by Anastasia Constantinidou et al2 -- examined tumor samples from 385 premenopausal women with ER+, HER2- primary breast cancer who had not received chemotherapy. The results show EndoPredict accurately identified premenopausal women with and without affected lymph nodes who could safely avoid adjuvant chemotherapy as part of their treatment plans due to a very low recurrence risk.

“This important publication on the new EndoPredict data demonstrates our ongoing commitment to advance precision medicine for patients with breast cancer,” said Dr. Ralf Kronenwett, director of International Medical Affairs, Myriad Genetics. “In light of mounting clinical recommendations to reduce overtreatment in breast cancer, the results are particularly encouraging. With around a third of all new breast cancer cases occurring in patients aged 54 or younger3, using EndoPredict among premenopausal women provides important insights to inform personalized treatment, including whether there’s a benefit to using chemotherapy or not.”

The study shows that patients with EndoPredict low-risk scores had a 97% distant recurrence free survival (DRFS) versus 76% for high-risk patients. Importantly, 19% of node-positive premenopausal patients had EndoPredict low-risk scores with 100% DRFS and were able to safely avoid chemotherapy and continue onto endocrine therapy alone.

Another key result from an exploratory subgroup analysis within the study found similar DRFS rates in low-risk patients with or without ovarian function suppression (OFS), with less than 5% distant recurrence after 10 years in both groups.

“This important study shows that premenopausal patients with a low-risk EndoPredict score have a good long-term outcome without chemotherapy and may be considered for treatment with endocrine therapy only,” said Dr. Anastasia Constantinidou, Bank of Cyprus Oncology Centre and Cyprus Cancer Research Institute. “These findings are relevant to better inform personalized treatment decisions for a large proportion of premenopausal women with ER+, HER2- early-stage breast cancer.”