Adjuvant Capecitabine for Early Breast Cancer: 15-Year Overall Survival Results From a Randomized Trial

Abstract

Purpose: Few data are available regarding the influence of adjuvant capecitabine on long-term survival of patients with early breast cancer.

Methods: The Finland Capecitabine Trial (FinXX) is a randomized, open-label, multicenter trial that evaluates integration of capecitabine to an adjuvant chemotherapy regimen containing a taxane and an anthracycline for the treatment of early breast cancer. Between January 27, 2004, and May 29, 2007, 1,500 patients with axillary node-positive or high-risk node-negative early breast cancer were accrued. The patients were randomly allocated to either TX-CEX, consisting of three cycles of docetaxel (T) plus capecitabine (X) followed by three cycles of cyclophosphamide, epirubicin, and capecitabine (CEX, 753 patients), or to T-CEF, consisting of three cycles of docetaxel followed by three cycles of cyclophosphamide, epirubicin, and fluorouracil (CEF, 747 patients). We performed a protocol-scheduled analysis of overall survival on the basis of approximately 15-year follow-up of the patients.

Results: The data collection was locked on December 31, 2020. By this date, the median follow-up time of the patients alive was 15.3 years (interquartile range, 14.5-16.1 years) in the TX-CEX group and 15.4 years (interquartile range, 14.8-16.0 years) in the T-CEF group. Patients assigned to TX-CEX survived longer than those assigned to T-CEF (hazard ratio 0.81; 95% CI, 0.66 to 0.99; P = .037). The 15-year survival rate was 77.6% in the TX-CEX group and 73.3% in the T-CEF group. In exploratory subgroup analyses, patients with estrogen receptor-negative cancer and those with triple-negative cancer treated with TX-CEX tended to live longer than those treated with T-CEF.

Conclusion: Addition of capecitabine to a chemotherapy regimen that contained docetaxel, epirubicin, and cyclophosphamide prolonged the survival of patients with early breast cancer.

Trial registration: ClinicalTrials.gov NCT00114816.

FIG 1.

CONSORT diagram. CEF, cyclophosphamide and epirubicin plus fluorouracil; CEX, cyclophosphamide and epirubicin plus capecitabine; ITT, intention-to-treat patient population; T, docetaxel; TX, docetaxel plus capecitabine.

FIG 2.

OS. The 5-year, 10-year, and 15-year survival rates are shown. Patients censored are indicated with a bar. CEF, cyclophosphamide and epirubicin plus fluorouracil; CEX, cyclophosphamide and epirubicin plus capecitabine; HR, hazard ratio; OS, overall survival; T, docetaxel; TX, docetaxel plus capecitabine. Adjuvant capecitabine added to conventional chemotherapy improves survival of patients with early breast cancer.

FIG 3.

Exploratory analyses of OS in subgroups. CEF, cyclophosphamide and epirubicin plus fluorouracil; CEX, cyclophosphamide and epirubicin plus capecitabine; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; HR, hazard ratio; OS, overall survival; PR, progesterone receptor; T, docetaxel; TX, docetaxel plus capecitabine.

FIG A1.

OS in selected subgroups: (A) patients with ER-positive and/or PR-positive , HER2-negative cancer, (B) patients with ER-positive and/or PR-positive, HER2-positive cancer, (C) patients with ER-negative, PR-negative, and HER2-positive cancer, and (D) patients with ER-negative, PR-negative, and HER2-negative cancer. Patients censored are indicated with a bar. CEF, cyclophosphamide and epirubicin plus fluorouracil; CEX, cyclophosphamide and epirubicin plus capecitabine; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; HR, hazard ratio; PR, progesterone receptor; OS, overall survival; T, docetaxel; TX, docetaxel plus capecitabine.