Invited discussant Anne Blaes, MD, of the University of Minnesota, Minneapolis, emphasized the main takeaway finding of the combined updated analysis of the SOFT and TEXT trials. “In early-stage estrogen receptor–positive breast cancer, premenopausal women who don’t require chemotherapy do very well, with a 95% survival rate at 12 years.”

Dr. Blaes continued: “Ovarian suppression plus aromatase inhibitors continue to be superior to tamoxifen in preventing recurrence and in overall survival, with the magnitude being the greatest in those younger than age 35 receiving chemotherapy. These data continue to support the superiority of ovarian function suppression paired with an aromatase inhibitor vs tamoxifen,” she said.

Anne Blaes, MD

This finding is consistent with earlier analyses of the SOFT and TEXT trials and with randomized studies that compare aromatase inhibitors vs tamoxifen in postmenopausal patients. It is also consistent with the Early Breast Cancer Trialists’ Collaborative Group meta-analysis reported by Rosie Bradley, where an aromatase inhibitor was found to be superior to tamoxifen in premenopausal women with estrogen receptor–positive breast cancer.

Questions Remain

“In the current era, where most women with early-stage estrogen receptor–/progesterone receptor–positive breast cancer received neoadjuvant chemotherapy, is ovarian function suppression plus aromatase inhibitor necessary if a pathologic complete response is achieved,” she asked. “Other remaining questions raised by these studies is what is the optimal duration of endocrine therapy? How does abemaciclib, recently approved in the adjuvant setting, fit into this equation?”

DISCLOSURE: Dr. Blaes reported no conflicts of interest.