Using Oncotype DX breast recurrence score® assay to define the role of neoadjuvant endocrine therapy in early-stage hormone receptor-positive breast cancer

PurposeThe role of neoadjuvant endocrine therapy in the treatment of patients with early-stage, hormone receptor-positive (HR +) breast cancer is not well defined. Tools to better determine which patients may benefit from neoadjuvant endocrine therapy versus chemotherapy or upfront surgery remain an unmet need.MethodsWe assessed the rate of clinical and pathologic complete response (cCR, pCR) among a pooled cohort of patients with early-stage HR + breast cancer who had been randomized to neoadjuvant endocrine therapy or neoadjuvant chemotherapy in two earlier studies to understand better how outcomes varied by Oncotype DX Breast Recurrence Score (R) assay.ResultsWe observed that patients with intermediate RS results had no statistically significant differences in pathologic outcomes at the time of surgery based on whether they received neoadjuvant endocrine therapy or neoadjuvant chemotherapy, suggesting that a subgroup of women with a RS 0-25 may omit chemotherapy without compromising outcomes.ConclusionThese data suggest that Recurrence Score (R) (RS) results may serve as a useful tool in treatment decision-making in the neoadjuvant setting.

Automated summary

This study evaluated the clinical and pathologic complete response rates among early-stage HR + breast cancer patients who had been randomized to neoadjuvant endocrine therapy or neoadjuvant chemotherapy. Results showed that patients with intermediate RS results did not have significant differences in pathologic outcomes based on treatment type, suggesting that women with RS 0-25 may be able to omit chemotherapy without compromising outcomes.