AbstractBackground and objective
The important characteristics of breast cancer is its heterogeneity and attitude of response to neoadjuvant chemotherapy (NAC). We analyzed the patterns of tumor shrinkage as a prognostic indicator after NAC for luminal breast cancer.Methods and results
Of the 503 patients who had received NAC in our hospital between January 2000 and December 2007, 142 luminal breast cancer were included in this study. Luminal breast cancer was defined as ER and/or PgR-positive in more than 10% of cancer cells and HER2 negative (IHC 0, 1+ or FISH < 2.0). Before and after NAC, the primary lesion was evaluated by enhanced MRI. The median follow-up period was 45.9 months. Thirty-two patients (22.5%) experienced recurrence after a median DFI of 43.1 months. The 5-year survival rate was 90.6%. The median age was 49 years, all patients received anthracycline anticancer drugs and 127 patients received taxane. The primary lesion was evaluable by imaging in 138 patients, 64 patients who experienced simple concentric tumor shrinkage, achieved a significantly more favorable histologic response to chemotherapy. Multivariate analysis identified strong ER positivity and the number of lymph node metastases as significantly favorable and unfavorable prognostic factors (P = 0.021, P = 0.049, respectively). Patients who did not experience simple concentric tumor shrinkage tended to have a poor prognosis (P = 0.053).Discussion
The results suggest that concentric tumor shrinkage tends to be associated with a favorable prognosis, whereas scattered residual cancer cells are resistant to chemotherapy.