Background: As anthracyclines and taxanes are frequently used in the adjuvant and first-line metastatic settings, capecitabine and vinorelbine are frequently used as monotherapy and in combination for metastatic breast cancer (MBC). In the absence of comparative, phase III data, retrospective analyses and cross-trial comparisons provide the only indication of the relative efficacy of these options.
Methods: We reviewed studies evaluating the 2 agents alone or in combination in MBC.
Results: We identified 6 capecitabine and 2 vinorelbine phase III trials, numerous phase II monotherapy studies and 35 phase I/II studies exploring capecitabine-vinorelbine combination therapy (1 with trastuzumab in HER2-positive MBC).
Conclusion: For monotherapy, the limited, retrospective comparative evidence supported by consistent prospective data suggests that capecitabine is more effective than vinorelbine. Comorbidities, organ function tolerability, tumour biology and patient characteristics should also inform treatment choice. If combination therapy is deemed clinically appropriate, intravenous vinorelbine with capecitabine may be considered, potentially improving efficacy compared with monotherapy, but at the cost of increased toxicity. Randomised evaluation versus capecitabine monotherapy is ongoing. In contrast, cross-trial comparison suggests that addition of oral vinorelbine to capecitabine adds haematological toxicity without apparently improving efficacy in pretreated MBC. Data from small, single-arm, phase II studies in the first-line setting are more encouraging. In summary, the strongest clinical data support capecitabine monotherapy in the majority of patients. In certain populations, a capecitabine-vinorelbine combination may be appropriate but requires further validation in randomised trials.