Predictors of complete response to neoadjuvant chemotherapy in Breast Cancer: A National Cancer Database (NCDB) analysis

Purpose: Pathologic Complete Response (PCR) following Neoadjuvant chemotherapy (NAC) for breast cancer has been associated with improved survival. The objective was to characterize those patients receiving NAC and analyze predictors of PCR. Patients and methods: Patients with clinical stage I-IIIC breast cancer who received NAC from 2004-2011 were identified from the National Cancer Database (NCDB). Multivariable analysis identified factors predicting PCR after NAC. Results: Of 49,850 patients, mean age was 53 (SD±13 years). Ductal carcinoma comprised 78% of tumors. Clinical stage I, II, and III were represented in 11%, 52%, and 37% of patients, respectively. Estrogen receptor was expressed in 60% of tumors (ER+). HER2 overexpression (HER2+) was seen in 8% of tumors and 7% of patients had triple negative disease (ER-/PR-/HER2-). Multivariable analysis was performed among 13,825 women with PCR data to identify significant predictors of response to NAC. Strong predictors of PCR (OR>1.5) included absence of lymphovascular invasion (LVI), early-stage disease, and ER-/PRstatus, whereas well and moderately differentiated tumors strongly predicted (OR<0.67) partial or no PCR. Conclusion: In a large cohort of women with breast cancer treated with NAC, PCR is most often seen in patients with hormone receptor negative, early clinical stage disease without LVI. Marissa K Srour; Jeffrey Johnson; Alice Chung; Armando E Giuliano; Farin Amersi* Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California, USA Introduction Neoadjuvant Chemotherapy (NAC) for breast cancer is used to downstage locally advanced disease to improve candidacy for breast conserving surgery (BCS)[1]. Although several studies have shown no survival benefit of NAC compared to adjuvant chemotherapy [1-6], achieving a pathologic complete response (PCR) following NAC has been associated with improved survival [1,2]. PCR has been proposed as a surrogate endpoint for prediction of long-term clinical benefit, including disease-free survival and overall survival [1-3]. While no studies have validated PCR as an endpoint for survival, the association between PCR and long-term outcomes is strongest in patients with triplenegative and HER2-positive breast cancer [1].