345P - Clinical Usefulness of Ajcc Response Criteria in Stage Ii/Iii Breast Cancer Patients Who Treated with Long Course Neoadjuvant Chemotherapy

Abstract

ABSTRACT Aim: Neoadjuvant chemotherapy (NAC) is a standard therapy for American Joint Committee on Cancer (AJCC) stage II or III breast cancer. Response to NAC is a useful prognostic marker for relapse and overall survival in breast cancer patients. To improve the outcome of NAC, extended cycles of neoadjuvant chemotherapy was introduced. Recently, six to eight cycles of NAC has become the standard treatment in practice. The purpose of this study is to evaluate the clinical usefulness of AJCC response criteria in extended course (≥6 cycles) NAC. Methods: Clinical stage II or III breast cancer patients who received NAC of 6 cycles or more were enrolled. AJCC response after NAC and the clinicopathological factors of these patients were reviewed retrospectively. AJCC response criteria for NAC were adopted from the AJCC 7th edition: complete response (CR), absence of invasive carcinoma in both breast and lymph node; partial response (PR), decrease in either or both T or N stage; no response (NR), no change or increase in either or both T or N stage. Results: From January 2009 to December 2010, 183 patients were enrolled in the study with median follow up period of 38.0 months. Current gold standard for evaluating response to NAC is pathologic complete response (pCR) versus non-pCR. Twenty two patients (12.0%) and 161 patients (88%) belonged to pCR and non-pCR, respectively. On the other hand CR, PR, and NR by AJCC response criteria were consisted of 22 (12.0%), 123 (67.2%), and 38 (20.8%) patients respectively. The 3-year relapse free survival (RFS) rates were 90.9% in CR, 80.8% in PR, and 48.5% in NR. AJCC response was significantly associated with relapse free survival (RFS) (P Conclusions: AJCC response criteria is a useful clinical prognostic marker for RFS in 6 or more cycles of NAC in stage II/III breast cancer. AJCC criteria is a simple, eidetic and easily reproducible tool for response evaluation for the breast cancer patients in NAC setting compared with classically used various methods. Disclosure: All authors have declared no conflicts of interest.