Assessment of Predictive Factors for Response to Neoadjuvant Chemotherapy in Breast Cancer

Abstract

The early identification of breast cancer patients who will not respond to neoadjuvant chemotherapy is valuable for timely change in management strategies. Reliable clinical and pathological markers predictive of response to treatment have considerable potential for practical clinical use. Our longitudinal study aimed to assess clinical, pathological, and immunohistological factors predictive of chemotherapy response. Thirty Five patients of breast cancer underwent six cycles of Taxotere, Adriamycin, and Cyclophosphamide (TAC) based neoadjuvant chemotherapy (Docetaxel 75 mg/m2, Doxorubicin 50 mg/m2 or Epirubicin 100 mg/m2 and Cyclophosphamide 500 mg/m2) every three weeks followed by surgery. Histopathological response was assessed after surgery. At a follow up of 12 months, association between factors was tested with Fisher exact test, survival analysis was done with Kaplan Meier analysis and significance was tested by log rank test. Five patients out of 35 had pathological complete response (pCR). 14.8% of all T4 disease (P = 0.043) and 22.7% of all Estrogen receptor (ER) negative patients had pCR (P = 0.025). Among all patients showing pCR, four patients (80%) had Grade III tumors (P = 0.018) while all five patients had high Ki67 index (P = 0.032). At 12 months, the mean estimated overall survival came out to be 11.6 months. Mean estimated disease free survival was less for patients with pCR (7.2 months) vs. partial response (10.1 months) (P = 0.44). Our study concluded that tumors with larger size, higher stage, higher grade, ER negativity and higher proliferation index had better response to chemotherapy but these tumors also had a trend towards early relapse.