Capecitabine monotherapy: safe and effective treatment for metastatic breast cancer

Optimal management for metastatic breast cancer frequently involves cytotoxic chemotherapy. Over the years, several complex multidrug regimens have been developed that were based upon a rationale of synergistic antitumor activity and nonoverlapping toxicities. However, recently the clinical value of these complex regimens has been called into question as several drugs used alone (monotherapy) or in sequence (serial single agent) have been shown to be both efficacious and better tolerated. Capecitabine (an orally administered fluoropyrimidine carbamate) is one such agent that has been proven to be effective when used alone for metastatic breast cancer, metastatic colorectal cancer, and adjuvant colon cancer. In this review, published (or reported in abstract form) data examining various aspects of clinical response and tolerability with single-agent capecitabine for (primarily) first- and second-line metastatic breast cancer are examined. For the most part, response rates are comparable with those of the more complex regimens. Dose reductions from the labeled dose of 1,250 mg/m(2) twice daily are relatively common. Toxicities (following dose reductions if needed) are generally manageable, even by more frail patients. Elderly patients are more likely to have impaired renal function or be receiving warfarin treatment, and special attention to these factors is warranted. Nonetheless, the drug administered alone is a reasonable choice when single-agent chemotherapy is entertained as a treatment option for metastatic breast cancer, including in the first-line setting.