Key clinical point: Patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (BC) who achieved pathological complete response (pCR) after 12 weeks of conventional chemotherapy-free, de-escalated, neoadjuvant anti-HER2 treatment can forgo adjuvant chemotherapy.
Major finding: Risk for invasive disease-free survival (iDFS) was significantly lower in patients who did vs did not achieve pCR (unadjusted hazard ratio [HR] 0.40; 95% CI 0.18-0.85). Among patients who achieved pCR, iDFS rates were similar in those who did vs did not receive adjuvant chemotherapy (unadjusted HR 1.15; 95% CI 0.27-4.81).
Study details: Findings are from the phase 2, WSG-ADAPT-TP trial including 375 patients with HR+/HER2+ early BC who were randomly assigned to receive 12 weeks of trastuzumab-emtansine with or without endocrine therapy (ET) or trastuzumab+ET in a neoadjuvant setting.
Disclosures: This study was supported by F. Hoffmann-La Roche Ltd. The authors declared serving in consulting or advisory roles, receiving research funding, travel and accommodation expenses, or honoraria, or having other ties with several sources, including Roche.
Source: Harbeck N et al on behalf of the WSG-ADAPT investigators. De-escalated neoadjuvant trastuzumab-emtansine with or without endocrine therapy versus trastuzumab with endocrine therapy in HR+/HER2+ early breast cancer: 5-year survival in the WSG-ADAPT-TP trial. J Clin Oncol. 2023 (Feb 21). Doi: 10.1200/JCO.22.01816