Pathological complete response, long-term outcomes, and recurrence patterns in HER2-low versus HER2-zero breast cancer after neoadjuvant chemotherapy.

BACKGROUND: The interest in HER2-low breast cancer (BC) has increased in recent years with the development of novel anti-HER2 antibody-drug conjugates. Here, we investigated the clinical outcomes and relapse patterns of patients with HER2-low or -zero BCs in an Asian population. METHODS: We retrospectively identified HER2-low or -zero BC patients with stage I-III tumours who were treated with neoadjuvant chemotherapy and underwent curative surgery, between 2014 and 2018 at Asan Medical Center, Seoul, Korea. RESULTS: A total of 818 and 754 HER2-zero and HER2-low BC patients, respectively, were consecutively included in this analysis. The HER2-low group had more hormone receptor [HR]-positive patients (81% versus 56%, P < 0.001). The HER2-zero group had a higher proportion of patients who achieved pathological complete response (pCR) (14.7% versus 9.8%, P = 0.003); however, no significant differences of pCR rate by HER2 status were identified in the HR-positive (P = 0.4) and HR-negative groups (P = 0.3) when analysed separately. The HER2-low BC cases had higher 5-year overall survival (OS) and disease-free survival (DFS) rates (P < 0.001 for OS; P = 0.002 for DFS); however, no differences were observed in terms of OS and DFS by HER2 status in the HR-positive group (P = 0.21 for OS and P = 0.66 for DFS). CONCLUSIONS: Our current findings do not support that HER2-low BC had different biology and clinical features compared to HER2-zero BC in patients who treated with neoadjuvant chemotherapy. However, the prognostic impact of HER2-low status in BC remains controversial; thus warranting further research.

Patient-reported outcomes from a randomized trial of neoadjuvant atezolizumab-chemotherapy in early triple-negative breast cancer.

Patient-reported outcomes data assessing patients' experience of immunotherapy treatment burden in potentially curable early-stage triple-negative breast cancer (TNBC) are lacking. These patient-reported data inform clinical benefit and decision-making for adding atezolizumab to neoadjuvant chemotherapy in early-stage TNBC. IMpassion031 (NCT03197935) randomly assigned patients with stage II/III TNBC (T2-T4d primary tumors) to 5 cycles (4 weeks/cycle) of every 2-week neoadjuvant atezolizumab 840 mg or placebo with weekly nab-paclitaxel (3 cycles) followed by every 2-week dose-dense doxorubicin+cyclophosphamide (2 cycles). After surgery, the atezolizumab-chemotherapy arm received atezolizumab 1200 mg every 3 weeks (11 cycles). The placebo-chemotherapy arm was observed under standard of care. To assess treatment burden from the patients' perspective, which comprised measures of the treatment-related impact on patients' functioning and health-related quality of life (HRQoL), as well as patients' experience of treatment-related symptoms plus their associated bother, patients completed the EORTC QLQ-C30 and FACT-G single-item GP5. Predefined secondary endpoints included mean and mean change from baseline values in the QLQ-C30 function (role and physical) and global health status/quality of life scales. Exploratory endpoints included mean and mean change from baseline in treatment-related symptoms, and treatment side effect bother. Mean physical, role function, and HRQoL were similar between arms at baseline and throughout treatment. In the neoadjuvant period, both arms exhibited clinically meaningful declines of similar magnitude from baseline in physical, role function, and HRQoL, and reported similar treatment side effect to bother at each visit. Improved pathologic complete response from adding atezolizumab to neoadjuvant chemotherapy for early-stage TNBC occurred without imposing additional treatment burden on patients.