Key clinical point: Postmenopausal patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2−) breast cancer (BC) who achieve a preoperative endocrine prognostic index (PEPI) score of 0-1/pathological complete response (pCR) with only neoadjuvant endocrine therapy (NET) can be safely treated without adjuvant chemotherapy.
Major finding: After a median follow-up of 60 months, the 5-year recurrence-free survival (RFS) improved significantly in patients who had PEPI 0-1/pCR without chemotherapy vs PEPI ≥2 (hazard ratio 0.18; P = .028). In patients who had PEPI ≥2, the 5-year RFS was similar regardless of the receipt of adjuvant chemotherapy ( P = .432).
Study details: Findings are from a phase 2 trial including 352 postmenopausal women with early-stage, strongly ER+ and HER2− BC who received NET for 4 months before surgery; after surgery, patients with PEPI 0-1/pCR and PEPI ≥2 were recommended only adjuvant ET and adjuvant ET±chemotherapy, respectively.
Disclosures: This study was supported by Novartis. The authors declared no conflicts of interest.
Source: Wang X et al. Neoadjuvant endocrine therapy for strongly hormone receptor-positive and HER2-negative early breast cancer: results of a prospective multi-center study. Breast Cancer Res Treat. 2022 (Aug 2(. Doi: 10.1007/s10549-022-06686-1