Capecitabine in early breast cancer: A meta-analysis of randomised controlled trials

Capecitabine is an effective therapy for metastatic breast cancer. Its role in early breast cancer is uncertain due to conflicting data from randomised controlled trials (RCTs).

PubMed and major conference proceedings were searched to identify RCTs comparing standard chemotherapy with or without capecitabine in the neoadjuvant or adjuvant setting. Hazard ratios (HRs) for disease-free survival (DFS) and overall survival (OS), as well as odds ratios (ORs) for toxicities were extracted or calculated and pooled in a meta-analysis. Subgroup analysis compared triple-negative breast cancer (TNBC) to non-TNBC and whether capecitabine was given in addition to or in place of standard chemotherapy. Meta-regression was used to explore the influence of TNBC on OS.

Eight studies comprising 9302 patients were included. In unselected patients, capecitabine did not influence DFS (hazard ratio [HR] 0.99, p = 0.93) or OS (HR 0.90, p = 0.36). There was a significant difference in DFS when capecitabine was given in addition to standard treatment compared with in place of standard treatment (HR 0.92 versus 1.62, interaction p = 0.002). Addition of capecitabine to standard chemotherapy was associated with significantly improved DFS in TNBC versus non-TNBC (HR 0.72 versus 1.01, interaction p = 0.02). Meta-regression showed that adding capecitabine to standard chemotherapy was associated with improved OS in studies with higher proportions of patients with TNBC (R = -0.967, p = 0.007). Capecitabine increased grade 3/4 diarrhoea (odds ratio [OR] 2.33, p < 0.001) and hand-foot syndrome (OR 8.08, p < 0.001), and resulted in more frequent treatment discontinuation (OR 3.80, p < 0.001).

Adding capecitabine to standard chemotherapy appears to improve DFS and OS in TNBC, but increases adverse events in keeping with its known toxicity profile.