ASCO 2021: Survival Outcomes With De-escalated Neoadjuvant Treatment of Early Breast Cancer
Posted: Monday, June 7, 2021
Nadia Harbeck, MD, of the University of Munich, and colleagues reported “excellent” pathologic complete response and survival rates in patients with hormone receptor–negative, HER2-positive early breast cancer who received de-escalated neoadjuvant chemotherapy plus pertuzumab and trastuzumab irrespective of further chemotherapy use. The first survival data from the multicenter phase II WSG-ADAPT-HR–/HER2+ trial were presented during the virtual edition of the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 503), also suggested that early pathologic complete response after neoadjuvant treatment with paclitaxel plus pertuzumab and trastuzumab seemed to be associated with improved outcomes and may serve as a predictive clinical marker for further de-escalation.
Patients were randomly assigned to receive pertuzumab plus trastuzumab with (n = 42) or without (n = 92) paclitaxel. Those who experienced a pathologic complete response were allowed to omit further chemotherapy. After a median follow-up of 5 years, no significant differences were observed in disease-free survival, distant disease-free survival, and overall survival between the treatment arms; a total of 13 and 7 invasive and distant disease–free survival events, respectively, were reported in the whole intention-to-treat population. Irrespective of the treatment arm, pathologic complete response after 12 weeks of treatment was reported to be strongly associated with improved invasive disease–free survival outcomes (5-year disease-free survival rate 98.5% vs. 82%).
Of the 69 patients who experienced a pathologic complete response, 39 received no further chemotherapy; according to the investigators, one distant relapse was observed in this patient population. No pathologic complete responses were observed in those treated with chemotherapy-free pertuzumab plus trastuzumab who had low HER2 expression and/or a basal-like subtype. Low HER2 expression and/or no early response seemed to be associated with worse distant (P = .029) and invasive (P = .068) disease–free survival outcomes in the total study population. No new safety signals were reported.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.