Purpose: The purpose of this study was to evaluate the predictive value of six different biological factors for neoadjuvant chemotherapy (NAC) in breast conservation treatment (BCT) for invasive breast cancer.
Materials and methods: Thirty invasive breast cancer patients (31 breasts) who received NAC as BCT and needle biopsy before chemotherapy were included in this study. Breast cancer tissue was obtained with an 18G core needle with ultrasound guidance. Patients received two to five courses of CAF (cyclophosphamide 600 mg/m(2), pirarubicin 20-40 mg, 5-fluorouracil 600 mg/m(2)). Tissue sections from formalin-fixed paraffin-embedded blocks were stained for the presence of estrogen receptor (ER), progesterone receptor (PgR), HER (human epidermal growth factor receptor)-2, p53 protein, Bcl-2, and MIB-1 (Ki-67). Tumor reduction rate was assessed by MRI before and after chemotherapy.
Results: The tumor reduction rate did not differ according to the number of courses of chemotherapy administered. In both the univariate and multivariate analyses, HER-2-negative status was the only significant predictive factor of response (P<0.05). There was no correlation between response and hormone receptors, MIB-1, p53 protein, or Bcl-2 expression.
Conclusion: This study suggests that breast cancer cells that overexpress HER-2 may be resistant to low-doses of anthracycline-based chemotherapy.