BACKGROUND: Patients with triple-negative breast cancer (TNBC) have a high relapse rate and poor outcomes after standard treatment. Capecitabine is a chemotherapy that is used widely in the treatment of metastatic breast cancer. In a recent study (SYSUCC-001), researchers evaluated the efficacy and safety of low-dose capecitabine maintenance after standard adjuvant chemotherapy in patients with early-stage TNBC.
METHODS: SYSUCC-001 was an open-label, multicenter, randomized, phase 3 study in China that included 443 patients with early-stage TNBC who had completed standard adjuvant chemotherapy. The patients were randomized in a 1:1 ratio to low-dose (650 mg/m2 twice daily) capecitabine continuously for 1 year (N = 222) or to an observational group (N = 221). The primary end point was 5-year disease-free survival (DFS). The secondary end points included distant DFS, overall survival (OS), locoregional recurrence-free survival, and adverse events.
RESULTS: Of the 443 patients who were randomized, 434 completed the trial. With a median follow-up of 61 months, 94 events were observed, including 38 events (37 disease recurrences and 32 deaths) in the capecitabine arm and 56 events (56 recurrences and 40 deaths) in the observation arm. The estimated 5-year DFS was significantly improved in the capecitabine group compared with the observation group (82.8% vs 73%, respectively; hazard ratio [HR] for risk of recurrence or death, 0.64; 95% confidence interval [CI], 0.42-0.95; P = .03). The estimated 5-year distant DFS rate was 85.8% and 75.8%, respectively (HR, 0.6; 95% CI, 0.38-0.92; P = .02). The treatment effects on DFS were consistent across all subgroups; however, capecitabine was not associated with significant improvement in the estimated 5-year OS or the estimated 5-year locoregional recurrence-free survival versus the observation group (85.5% vs 85% and 81.3% vs 80.8%, respectively). Low-dose capecitabine was generally well-tolerated. The most common capecitabine-related adverse event was hand-foot syndrome in 100 patients (45.2%), of which 7.7% were grade 3. Other common grade 1 or 2 adverse events in the capecitabine group included leukopenia (23.5%), elevated bilirubin (12.7%), abdominal pain or diarrhea (6.8%), and elevated alanine aminotransferase or aspartate transaminase levels (5%). “The current trial demonstrated that a year of capecitabine was tolerable for most women without significant treatment discontinuation due to toxicity,” stated the researchers.
Source: Wang X, Wang SS, Huang H, et al. Effect of capecitabine maintenance therapy using lower dosage and higher frequency vs observation on disease-free survival among patients with early-stage triple-negative breast cancer who had received standard treatment: the SYSUCC-001 randomized clinical trial. JAMA. 2021;325:50-58.