Outcomes With Chemotherapy May Differ by Menopausal Status: Report From RxPONDER
Posted: Friday, January 29, 2021
There seems to be a significant difference in the benefit of chemotherapy based on recurrence scores for women with breast cancer who are pre- or postmenopausal, according to the first results from the phase III RxPONDER trial. Although adjuvant chemotherapy can be de-escalated to endocrine therapy alone in patients who are postmenopausal, a disease-free survival benefit remains for chemoendocrine therapy in premenopausal patients. Kevin Kalinsky, MD, MS, of Emory University, Atlanta, and colleagues presented this work at the 2020 San Antonio Breast Cancer Symposium (Abstract GS3-00).
This prospective randomized trial recruited 5,083 women with hormone receptor–positive, HER2-negative breast cancer, one to three positive lymph nodes, and a recurrence score of up to 25. Women were randomly assigned 1:1 to receive either endocrine therapy or chemoendocrine therapy to assess the effect of chemotherapy on invasive disease–free survival.
After a median follow-up of 5.1 years, 447 invasive disease–free survival events were observed. On initial analysis, there was no statistically significant correlation found between chemotherapy benefit and continuous recurrence score. When adding menopausal status to the analysis, researchers found that higher recurrence scores were associated with a worse invasive disease–free survival (hazard ratio = 1.06), and chemotherapy was associated with an improvement in survival (hazard ratio = 0.81).
In postmenopausal women, chemoendocrine therapy seemed to offer no advantage when compared with endocrine therapy (hazard ratio = 0.97, P = .82), indicating no benefit from chemotherapy. The 5-year invasive disease–free survival rates were similar among the postmenopausal group, 91.6% and 91.9% in the chemoendocrine and endocrine therapy groups, respectively.
In premenopausal women, there appeared to be a significant benefit with chemoendocrine therapy compared with endocrine therapy alone (hazard ratio = 0.54, P = .0004), indicating an advantage to chemotherapy among this population. The 5-year invasive disease–free survival rate was 94.2% in the chemoendocrine therapy group and 89.0% in the endocrine therapy–alone group. Ovarian suppression was performed in 15.9% of the premenopausal women receiving endocrine therapy and 3.7% of women undergoing chemoendocrine therapy.
Disclosure: For a full list of authors’ disclosures, visit www.sabcs.org.
