Characterization of patients who received prior chemotherapy for advanced breast cancer (ABC) in BOLERO-2

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Abstrakt byl publikován rovněž v Supplementu časopisu
J Clin Oncol 31, 2013 (suppl; abstr 557)

Abstract

Background: In patients with hormone-receptor–positive (HR⁺) breast cancer, endocrine therapy is the standard of care both in the adjuvant setting and as first-line treatment for ABC. For selected HR⁺ patients with ABC, chemotherapy (CT) may be utilized if disease burden is high and rapid symptom control is required (Barrios CH. GAMO.2010). In the phase 3 BOLERO-2 study (NCT00863655), 1 line of prior CT in the ABC setting was allowed. This subset analysis examined disease characteristics and the efficacy of everolimus (EVE) plus exemestane (EXE) in patients who received CT for ABC prior to BOLERO-2 study entry. Methods: In BOLERO-2, 724 patients with HR⁺, human epidermal growth factor receptor-2–negative (HER2^–) ABC whose disease recurred or progressed during/after a nonsteroidal aromatase inhibitor were randomized 2:1 to EVE (10 mg/d) + EXE (25 mg/d) or placebo (PBO) + EXE. The primary endpoint was progression-free survival (PFS) by local investigator review and confirmed by blinded independent central review. Results: A subset of 186 patients (26%) received prior CT for ABC: 125 in the EVE + EXE group and 61 in PBO + EXE. In this subset, 54% (67 of 186) of patients received prior CT only in the advanced setting and 46% (58 of 186) of patients received prior CT in both the neoadjuvant/adjuvant and advanced settings. Incidences of visceral metastases (67% vs 56%), multiple metastases (79% vs 66%), and ≥ 4 metastatic sites (18.3% vs 15%) were higher in ABC patients with prior CT for ABC at study entry versus those with no prior CT for ABC. Disease recurrence < 6 months from initial diagnosis was recorded in 32.2% (n = 60) of prior CT patients versus 17.3% (n = 93) of patients with no prior CT. Median PFS (by local assessment) in patients who received prior CT for ABC was substantially longer with EVE + EXE versus PBO + EXE (6.1 vs 2.7 mo; HR = 0.38; 95% CI, 0.27-0.53). PFS by central review showed similar results (7.1 vs 2.8 mo, respectively; HR = 0.42; 95% CI, 0.27-0.65). Conclusions: These results demonstrate that patients with HR⁺, HER2^– ABC who received previous CT in the advanced setting had a higher tumor burden and derived clinically significant benefit from combination treatment with EVE + EXE. Clinical trial information: NCT00863655.