p53 Mutation and c-erbB2 Over-expression in Predicting Factor of Responsibility to Neoadjuvant Chemotherapy in Patients with Breast Cancer

ABSTRACT

PURPOSE: The predictive value of c-erbB2 over-expression, and p53 mutation, to the response rate to neoadjuvant chemotherapy, were assessed in patients with breast cancer. METHODS: Between January 2000 and June 2002, 185 patients, with breast cancer, were put forward for two commonly used chemotherapy regimens prior to surgery. The first 135 received the CMF (cyclophosphamide 600 mg/m2, methotraxate 40 mg/m2, 5-FU 500 mg/m2) regimen, and the remaining 50 the CAF (cyclophosphamide 600 mg/m2, adriamycin 50 mg/m2, 5-FU 500 mg/m2) regimen. The expressions of the estrogen receptor (ER), progesterone receptor (PR), p53 mutation and c-erbB2, were evaluated by immunohistochemistry of needle biopsy samples prior to neoadjuvant chemotherapy. Tumor response was categorized according to the WHO criteria, using the largest diameter in ultrasonography or magnetic resonance imaging. RESULTS: The mean age of the patients in the CMF and CAF groups were 48.8 and 47.4 years. Forty eight (35.6%) and 24 (48.0%) of the patients, in the CMF and CAF groups, respectively, had pathologically partial or complete responses. The tumor size, axillary lymph nodes, lymphatic and vascular invasions, as clinicopathological factors, were significantly correlated with the response to chemotherapy in the CAF group. The absences of ER or PR were also significantly associated with a remission in both the CMF and CAF groups. p53 mutation was not correlated to the response rate of either chemotherapy regimen. There was no significant relationship between the expression of c-erbB2 and the response rate in the CMF group, but a higher percentage of patients with c-erbB2 positive tumors had a response to the CAF regimens. CONCLUSION: p53 mutation is not significantly associated with tumor response, but the over-expression of c-erbB2 can predict the response to the different chemotherapies used in breast cancer.