Background: Standard adjuvant chemotherapy regimens for patients with moderate-to-high-risk early breast cancer typically contain a taxane, an anthracycline, and cyclophosphamide. We aimed to investigate whether integration of capecitabine into such a regimen enhances outcome.
Methods: In this open-label trial, we randomly assigned (centrally by computer; stratified by node status, HER2 status, and centre) 1500 women with axillary node-positive or high-risk node-negative breast cancer to either three cycles of capecitabine and docetaxel followed by three cycles of cyclophosphamide, epirubicin, and capecitabine (capecitabine group, n=753), or to three cycles of docetaxel followed by three cycles of cyclophosphamide, epirubicin, and fluorouracil (control group, n=747). The primary endpoint was recurrence-free survival. A planned interim analysis was done after 3 years' median follow-up. Efficacy analyses were by modified intention to treat. The study is registered with ClinicalTrials.gov, number NCT00114816.
Findings: Two patients in each group were excluded from efficacy analyses because of withdrawal of consent or distant metastases. After a median follow-up of 35 months (IQR 25.5-43.6), recurrence-free survival at 3 years was better with the capecitabine regimen than with control (93%vs 89%; hazard ratio 0.66, 95% CI 0.47-0.94; p=0.020). The capecitabine regimen was associated with more cases of grade 3 or 4 diarrhoea (46/740 [6%] vs 25/741 [3%]) and hand-foot syndrome (83/741 [11%] vs 2/741 [<1%]) and the control regimen with more occurrences of grade 3 or 4 neutropenia (368/375 [98%] vs 325/378 [86%]) and febrile neutropenia (65/741 [9%] vs 33/742 [4%]). More patients discontinued planned treatment in the capecitabine group than in the control group (178/744 [24%] vs 23/741 [3%]). Four patients in the capecitabine group and two in the control group died from potentially treatment-related causes.
Interpretation: The capecitabine-containing chemotherapy regimen reduced breast cancer recurrence compared with a control schedule of standard agents. Capecitabine administration was frequently discontinued because of adverse effects.
Funding: Roche, Sanofi-Aventis, AstraZeneca, Cancer Society of Finland.