- For estrogen receptor-positive (ER+) breast cancer, neoadjuvant chemotherapy (NACT) bests neoadjuvant endocrine therapy (NET) for tumor downstaging and complete response in matched patients.
Why this matters
- The results run counter to the idea that patients with ER+, HER2- tumors have similar downstaging rates with a short course of NET vs NACT.
- Interest is in NET in this patient population despite inconsistent data on downstaging and long-term outcomes and no data from large prospective randomized trials comparing NACT and NET.
- 63% received NACT, 29% had NET, 8% had them sequentially.
- Women in the NET group were significantly older, had lower clinical stage (both P<.0001>
- Clinical downstaging more frequent with NACT (20/51, 39.2%) vs NET (11/51, 21.6%) in matched patients (P=.032).
- Clinical complete response rates were 3.9% with NET (2/51) vs 37.3% with NACT (19/51; P<.0001>
- Pathologic complete response rates were 2.1% for NET and NACT, with 1 patient in each group.
- 25.5% in NET group had partial mastectomy vs 27.5% in NACT group (P=.05).
- Prospective database study of patients with ER+/HER2- breast cancer undergoing neoadjuvant treatment, 2012-2017.
- Patients matched for age, stage, grade.
- Funding: None.
- No randomization, relatively small sample.