Abstract P2-12-02: Efficacy, safety and survival of neoadjuvant chemotherapy with different estrogen deprivation stratified by menstrual status versus chemotherapy alone in locally advanced breast cancer (SHPD002)—— A randomized multicentre, open-label, phase 3 Triab

Abstract

Abstract BackgroundAchieving pathologic complete response (pCR) because of neoadjuvant therapy has been correlated with long-term clinical benefit, however, luminal-like tumors achieve a lower rate of pCR in comparison with other subtypes. The Shanghai Pudong (SHPD) 002 trial compares neoadjuvant chemotherapy concurrently with or with different estrogen deprivation therapy separately in premenopausal and postmenopausal patients with locally advanced breast cancer. MethodsIn this prospective, multicentre, neoadjuvant, phase III trial, 236 patients with locally advanced breast cancer were randomly assigned (2:1) to receive neoadjuvant chemotherapy (NCT) with gonadotropin-releasing hormone agonist (GnRHa) in premenopausal women or letrozole in postmenopausal women compared with chemotherapy alone. The primary endpoint was pCR (ypT0/is/ypN0). Secondary endpoints included disease-free survival, overall survival, and safety. This trial is registered with ClinicalTrials.gov, number NCT NCT02221999.Results A total of 236 patients were included. pCR was achieved by 20.4% in the chemotherapy plus ET group and 38.6% in the chemotherapy group. In postmenopausal patients, pCR was observed in 22.6% when treated with letrozole, 32.4% with NCT alone (p=0.276). Premenopausal patients with NCT and GnRHa achieved a significantly lower pCR of 18.8% than those of 42.9% in patients with NCT alone(p=0.003). A posthoc analysis showed CPS+EG score 0-3 was significantly more probable in patients with GnRHa (OR, 0.245; 95% CI, 0.072 to 0.832, P=0.024) than in those without GnRHa in the premenopausal patients who didn’t achieve near-pCR. After a median follow-up of 45 months, there was no significant difference concerning disease-free survival (DFS) (p=0.874) or overall survival (OS) (P =0.947) between the 2 postmenopausal groups. GnRHas significantly improved survival outcome in premenopausal patients (3-year OS, 100% with GnRHas, vs 88.2% without; log-rank p=0.034). Improved DFS (log-rank p = 0.001) and OS (log-rank p=0.003) were strongly associated with pCPS+EG score and GnRHa usage in premenopausal patients.ConclusionsConcurrent administration of GnRHas during neoadjuvant chemotherapy improves OS in premenopausal patients, though it does not increase the pCR rate. The adoption of the CPS+EG score may be a better surrogate endpoint for survival outcomes. The addition of letrozole to neoadjuvant chemotherapy confers no therapeutic advantage in terms of tumor response or survival outcome. Citation Format: Liheng Zhou, Shuguang Xu, Xiaohong Xue, Yinzhou Zhang, Bei Gu, Baoxing Lin, Junwen Bai, Hongwei Zhang, Kejin Wu, Yanping Lin, Yumei Ye, Yueyao Du, Xiaonan Sheng, Yaqian Xu, Jie Zhang, Wenjin Yin, Jinsong Lu. Efficacy, safety and survival of neoadjuvant chemotherapy with different estrogen deprivation stratified by menstrual status versus chemotherapy alone in locally advanced breast cancer (SHPD002)—— A randomized multicentre, open-label, phase 3 Triab [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-12-02.