The invited discussant of the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) meta-analysis, Ines Vaz-Luis, MD, PhD, of the Breast Cancer Survivorship Group, Gustave Roussy, Villejuif, France, pointed out that the benefit of ovarian suppression or ablation in reducing breast cancer recurrence has been known for decades. “The EBCTCG’s meta-analysis is a timely update incorporating data from newer practice-changing trials,” she said, adding that the study and its findings can inform practice in the direction of “moving toward a tailored approach for premenopausal women: not too much, not too little.”

Investigators examined two groups: women who were premenopausal without receiving chemotherapy or remained premenopausal after chemotherapy, and a group who were premenopausal before chemotherapy but whose menopausal status after chemotherapy was uncertain. In the former group of confirmed premenopausal women, there was a 9.8% absolute 15-year increased benefit in reducing recurrence with ovarian suppression or ablation. The benefit was larger for patients with node-positive tumors and for patients not treated with tamoxifen, although there was also a small effect in tamoxifen-treated patients. For the second group, women with uncertain menopausal status, only a 1.3% benefit was observed, she noted.

Remaining Questions, Next Steps

“So, we learned here that ovarian suppression works,” Dr. Vaz-Luis concluded. The caveat is that many of the older trials involved outdated chemotherapy regimens, which often resulted in chemotherapy-related amenorrhea. “The question now is how much effect ovarian suppression or ablation has against the background of endocrine therapy and chemotherapy,” she posed.

The SOFT trial¹ demonstrated that composite risk scores including factors such as nodal status, tumor size, hormone receptor status, grade, proliferation, and patient age may help to identify patients who will fare well with tamoxifen alone and those who will benefit from additional therapy in the form of ovarian suppression, Dr. Vaz-Luis said.

According to Dr. Vaz-Luis, there is an increasing trend to conduct trials that will stratify premenopausal patients according to risk, to better refine the role of ovarian suppression (especially in high-risk tumors) and the need for chemotherapy. “We need large integrated infrastructures, like the SOFT trial, to learn more about young women, but we need them to be patient-centered, decentralized, pragmatic, more sustainable, and associated with dynamic biologic (ie, adaptive) platforms,” she commented. The aim is to evolve to “more predictive, preventive, personalized, and participatory medicine.” 

DISCLOSURE: Dr. Vaz-Luis has served as a speaker or chair and received honoraria from Amgen, AstraZeneca, Pfizer/Edimark, Novartis, and Sandoz; has written for Pfizer/Edimark; has received research funding from Resilience; and has received travel funding from Novartis.

REFERENCE

1. Pagani O, Regan MM, Walley BA, et al: Adjuvant exemestane with ovarian suppression in premenopausal breast cancer. N Engl J Med 371:107-118, 2014.