Adjuvant treatment with platinum agents failed to improve outcomes in patients with basal subtype triple-negative breast cancer (TNBC) who had residual invasive disease after neoadjuvant chemotherapy, according to a study published in the Journal of Clinical Oncology.
Platinum agents proved no more effective than capecitabine and were associated with more severe toxicity in this trial (ClinicalTrials.gov identifier: NCT02445391).
The ECOG-ACRIN EA1131 trial included 308 patients with basal subtype, stage II-III TNBC who had at least 1 cm of residual disease in the breast after neoadjuvant chemotherapy.
The patients were randomly assigned to receive capecitabine for 6 cycles or a platinum agent (cisplatin or carboplatin) for 4 cycles.
The study’s primary endpoint was invasive disease-free survival (iDFS). At a median follow-up of 20 months, there were 120 iDFS events, which included 93 distant recurrences, 15 loco-regional recurrences, 5 invasive second primary cancers without recurrence, and 7 deaths without recurrence or a second primary cancer.
The 3-year iDFS rate was 42% in the platinum arm and 49% in the capecitabine arm (hazard ratio [HR], 1.06; 95% repeated CI, 0.62-1.81).
The 3-year relapse-free survival rate was 46% in the platinum arm and 49% in the capecitabine arm (HR, 0.99; 95% CI, 0.67-1.45). The 3-year overall survival rate was 58% and 66%, respectively (HR, 1.13; 95% CI, 0.71-1.79).
Myelosuppression, nausea, diarrhea, and palmar-plantar erythrodysesthesia syndrome were the most common adverse events observed with capecitabine. The most common toxicities seen with platinum agents were myelosuppression and nausea.
Grade 3/4 toxicities were more frequent with platinum therapy than with capecitabine — 26% and 15%, respectively. The most common of these events were anemia and leucopenia.
The data and safety monitoring committee recommended stopping the trial early because follow-up was unlikely to show that platinum agents were noninferior or superior to capecitabine.
“For now, the use of adjuvant platinum agents in unselected patients with TNBC remains investigational, and capecitabine remains the standard therapy,” the study authors wrote. “[E]A1131 lays the important groundwork for the next generation of studies addressing the critical need for more active and effective therapies for patients with high-risk TNBC.”
Disclosure: This research was supported by the National Cancer Institute. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Mayer IA, Zhao F, Arteaga CL, et al. Randomized phase III postoperative trial of platinum-based chemotherapy versus capecitabine in patients with residual triple-negative breast cancer following neoadjuvant chemotherapy: ECOG-ACRIN EA1131. J Clin Oncol. Published online June 6, 2021. doi:10.1200/JCO.21.00976