ASCO 2021: Adjuvant Capecitabine Versus Platinum-Based Chemotherapy for Residual Triple-Negative Breast Cancer
Posted: Friday, June 11, 2021
In patients with residual triple-negative breast cancer after neoadjuvant chemotherapy, the 3-year invasive disease–free survival rate was lower than expected regardless of whether adjuvant platinum-based chemotherapy or capecitabine was administered, according to the phase III EA1131 trial. Ingrid A. Mayer, MD, MSc, of Vanderbilt University, Nashville, and colleagues presented these results during the virtual edition of the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 605).
“Available data show that it is very unlikely that the study would be able to establish noninferiority of platinum-based chemotherapy to capecitabine,” the investigators commented. “In patients with triple-negative breast cancer, particularly basal subtype, with at least 1 cm residual disease after neoadjuvant chemotherapy and high risk of recurrence, adjuvant platinum-based chemotherapy does not improve outcomes.”
A total of 401 patients with stage II or III triple-negative breast cancer who had residual disease after completion of neoadjuvant taxane therapy with or without anthracycline-based chemotherapy were randomly assigned in a 1:1 ratio to receive platinum-based chemotherapy (carboplatin or cisplatin) or capecitabine. The majority of patients (77%) had basal subtype disease.
The overall incidence of any toxicity was similar between the treatment arms (platinum-based chemotherapy: 83%; capecitabine: 80%); however, grade 3 and 4 toxicities were reported more frequently with platinum-based chemotherapy than with capecitabine (25% vs. 15%). After a median follow-up of 18 months, a total of 113 invasive disease–free survival events were observed. The 3-year invasive disease–free survival rate was 40% with platinum-based chemotherapy and 44% with capecitabine. The hazard ratio was 1.09, and the probability of eventually rejecting the null of inferiority was 6%. Thus, it seemed unlikely the trial would show noninferiority or superiority of platinum-based chemotherapy; therefore, in March 2021, the data safety and monitoring committee recommended stopping the trial at the fifth interim analysis.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.