Integration of capecitabine (X) into adjuvant therapy comprising docetaxel (T) followed by 5-FU, epirubicin, and cyclophosphamide (CEF): Efficacy in patients with triple-negative breast cancer (BC).
531 Background: Interim data from this phase III randomized trial (FinXX) evaluating the integration of capecitabine into anthracycline-/taxane-based adjuvant therapy for early BC were recently published (Lancet Oncol 2009); the present subgroup analysis explores the efficacy results in patients with triple-negative BC. Methods: 1,500 patients with axillary node-positive or high-risk node-negative (tumor size > 20 mm, progesterone receptor-negative) BC were randomized to the X-containing regimen: 3x XT (X 900 mg/m2 bid d1–14 and T 60 mg/m2 iv d1, q21d) followed by 3x CEX (C 600 mg/m2 iv d1, E 75 mg/m2 iv d1 and X 900 mg/m2 bid d1–14, q21d; n = 753), or the control regimen: 3x T (80 mg/m2 iv d1, q21d) followed by 3x CEF (C 600 mg/m2, E 75 mg/m2 and F 600 mg/m2 all d1, q21d; n = 747) in January 2004 to May 2007. The primary endpoint was recurrence-free survival (RFS) and the median follow-up time 3 yrs. Results: RFS was significantly increased with the X-containing therapy compared with control (92.5% vs. 88.9%; Cox proportional hazards model hazard ratio [HR] 0.66, 95% CI 0.47–0.94; p = 0.020). Overall, patients without triple-negative disease (n = 1,294) had longer RFS than those with triple-negative cancer (n = 202; HR 0.43, 95% CI 0.29–0.63; p < 0.001). Within the triple-negative BC subgroup, patients in the X arm (n = 93) achieved a longer RFS than those in the control arm (n = 109; HR: 0.43, 95% CI 0.21–0.90; p = 0.024; 3-yr RFS 87.7% vs. 76.6%, respectively), representing a 57% reduction in the risk of breast cancer recurrence or death. RFS of patients with triple-negative BC treated with the X-containing regimen did not differ significantly from RFS of the FinXX study participants whose cancer was not triple negative (HR: 0.74, 95% CI 0.38-1.41; p = 0.357). Conclusions: In this explorative analysis the integration of X into adjuvant combination chemotherapy reduced the risk of breast cancer recurrence substantially compared with a control regimen of standard agents in patients with triple-negative early BC. The result needs to be confirmed in studies that address adjuvant X-containing chemotherapy for triple-negative BC.