Exact Sciences Corporation announced that data from the Rx for Positive Node, Endocrine Responsive Breast Cancer, or RxPONDER, trial successfully defined the benefit of chemotherapy in early-stage, node-positive breast cancer patients with Oncotype DX Breast Recurrence Score® results of 0 to 25. First results from the study, led by the independent SWOG Cancer Research Network, and sponsored by the National Cancer Institute (NCI), identified the majority of women with 1-3 positive nodes who received no benefit from chemotherapy.i The data will be presented on December 10 at the 2020 San Antonio Breast Cancer Symposium (SABCS). RxPONDER showed a different effect of chemotherapy based on Recurrence Score® results for postmenopausal and premenopausal women. Postmenopausal women with Recurrence Score results 0-25 were not observed to show benefit from chemotherapy and may avoid the associated side effects of the treatment. Importantly, no chemotherapy benefit was observed regardless of the number of affected nodes, tumor grade, or size. Two-thirds of the women in the trial were postmenopausal. The first results also demonstrated, after a median of five years of follow-up, that premenopausal women with Recurrence Score results 0-25 were observed to have a statistically significant chemotherapy benefit, with an average improvement in distant recurrence rates at 5 years of 3%. Approximately 85% of women with node- positive disease have Recurrence Score results of 0 to 25. ii Postmenopausal and premenopausal women with Recurrence Score results 26-100 were not included in the study because investigators reviewed prior studies and determined that this patient group had chemotherapy benefit. The SWOG investigators intend to publish the detailed RxPONDER results in a peer-reviewed publication. Approximately 25% of patients diagnosed with hormone receptor (HR)-positive, HER2-negative early breast cancer have tumor that has spread to their lymph nodes and two out of three are postmenopausal.iii The vast majority of these patients currently receive chemotherapy.iv RxPONDER is a prospective, randomized Phase III study conducted at 632 sites in nine countries – the United States, Canada, Mexico, Colombia, Ireland, France, Spain, South Korea, and Saudi Arabia. The study enrolled more than 5,000 women with up to three positive nodes. Women with a Recurrence Score result 0-25 were randomized for treatment with hormone therapy alone or chemotherapy followed by hormone therapy. Randomized patients were stratified based on their Recurrence Score result, menopausal status, and the type of lymph node surgery. The use of the Oncotype DX test in early-stage breast cancer is supported by prospective outcomes from more than 17,000 patients with node-positive disease and more than 83,000 patients with node-negative disease, including the TAILORx study. Results from TAILORx, published in 2018, showed that the Oncotype DX test identifies the vast majority of women with node-negative disease who receive no substantial benefit from chemotherapy (approximately 80%), as well as the important minority for whom chemotherapy can be life-saving.