Abstract P1-11-10: Sequential Versus Upfront Intensified Neoadjuvant Chemotherapy in Patients with Large Resectable or Locally Advanced Breast Cancer (INTENS), First Results from a Phase III Study of the Dutch Breast Cancer Trialists’ Group (BOOG)

Abstract

Abstract Background: Taxanes have an established role as (neo)-adjuvant treatment of breast cancer. In the NSABP-B30 and the BCIRG 005, adriamycin and cyclophosphamide followed by docetaxel (AC-T) was compared with docetaxel in combination with adriamycin and cyclophosphamide (TAC) in the adjuvant setting. AC-T outperformed TAC if TAC was given for 4 cycles (B-30). However, AC-T was not significantly different from TAC if TAC was given for 6 cycles (BCIRG 005). In the present study, we compared AC-T with 6 cycles of TAC in the neo-adjuvant setting. Methods: Women presenting with breast cancer, cT2≥3cm, cT3, cT4 and/or cN+, with measurable disease and no prior treatment, age ≥18 and ≥70 years and Karnofsky-Score ≥70% were eligible. Patients were randomized to AC (60/600 mg/m2 q3wk x 4 cycles) followed by T (100 mg/m2 q3wk x 4 cycles) or TAC (75/50/500 mg/m2 q3wk x 6 cycles). If indicated, trastuzumab and/or endocrine therapy were given as adjuvant treatment. The primary endpoint of this study was the pathologic complete response (pCR) rate to neoadjuvant chemotherapy at surgery. Safety data will be presented separately at a later date. Results: In total, 201 patients (n=100 AC-T, n=101 TAC) were included between February 2006 and April 2009. Baseline characteristics (ACT/TAC) were well balanced for age (median 49/49y), T-status (cT1-2 51/49%), N-status (cN0 37/40%), hormone receptor status (positive in 65/66%) and HER2 (positive in 28/18%). AC-T resulted in pCR of the breast in 28% of patients and TAC in 19% of patients (Odds ratio (OR) 1.61; 95% CI 0.79-3.33). In patients with positive lymph nodes in situ at start of chemotherapy (no sentinel node procedure), combined pCR of the breast and axilla was 19 % (n=42) and 13% (n=38). Conclusion: AC followed by T resulted in a higher pCR rate, though not statistically significant. Support: Unrestricted grants from sanofi-aventis NL BV and Amgen BV Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-11-10.