Efficacy and Safety of Capecitabine Alone or in Combination in Advanced Metastatic Breast Cancer Patients Previously Treated with Anthracycline and Taxane: A Systematic Review and Meta-Analysis

Background: Capecitabine is frequently used alone or combined with other chemotherapy agents for the treatment of metastatic breast cancer in relapsed patients. Objective: The objective of this meta-analysis is to evaluate the effectiveness and safety of capecitabine monotherapy versus combination in the treatment of metastatic breast cancer patients pretreated with anthracycline and taxane. Methods: Eligible randomized controlled trials examining the efficacy and safety of capecitabine alone compared to capecitabine combination were systematically searched. Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and grades 3-4 drug-related adverse events were the outcomes assessed. Results: A total of 6,714 patients of 9 trials were involved in the pooled analysis. Our findings demonstrated that capecitabine combination is significantly superior to capecitabine monotherapy in improving PFS (hazard ratio [HR] 1.32, 95% CI 1.13-1.54, p < 0.0001) and ORR (risk ratio [RR] 0.67, 95% CI 0.54-0.83, p < 0.001), but it was insignificant in OS (HR 1.09, 95% CI 0.98-1.22, p = 0.12). On the other hand, the incidence of non-hematological adverse events such as hand-foot syndrome and diarrhea was lower in capecitabine combination compared to capecitabine monotherapy. Conclusion: Capecitabine-based combination chemotherapy showed superiority over capecitabine monotherapy in terms of PFS and ORR, with no significant difference in OS. Non-hematological adverse effects such as hand-foot syndrome were fewer with a combination regimen. However, hematological adverse events were fewer with capecitabine monotherapy regimen.