Changes in Pathological Complete Response Rates after Neoadjuvant Chemotherapy for Breast Carcinoma over Five Years.

Jessica Naikan,John Mandeli,Mariya Rozenblit,Daniel C Mcfarland,Amy Tiersten,Ira Bleiweiss

doi:10.1155/2016/4324863

Abstract

Historically, neoadjuvant chemotherapy (NACT) was extrapolated from adjuvant regimens. Dual HER2 blockade and the introduction of carboplatin for triple negative breast cancers (TNBC) emerged by December 2013 and have improved pathological complete response (pCR) rates. The objective of this study was to assess the pCR rates before and after the introduction of these new neoadjuvant regimens. Materials and Methods. Stage I–III breast cancer patients who received NACT were analyzed for rates of pCR by clinical characteristics (i.e., age, BMI, axillary lymphadenopathy, and histologic subtype), by time period (1 = 3/2010–11/2013, 2 = 12/2013–3/2015), and by type of chemotherapy (e.g., anthracycline/taxane only, carboplatin-containing, and HER2 blockade). Results. 113 patients received NACT. Overall pCR rate was 26.5 percent (n = 30). The pCR rate increased from 14% to 43.1% (p = 0.001) from time period 1 to time period 2 and were associated with HER2 positivity (p = 0.003), receiving treatment during time period 2 (p = 0.001) and using an anthracycline/taxane plus additional agent type of regimen (p = 0.004). Conclusions. Our study revealed a significant difference in rates of pCR over five years. Window of opportunity trials and other trials that utilize pCR analysis should be encouraged.

Highlights

Neoadjuvant chemotherapy (NACT) was initially developed as a component of combined modality treatment for locally advanced breast cancer (LABC) that either was inoperable at presentation or required extended radical surgery [1]
The landmark trial, National Surgical Adjuvant Breast Project (NSABP) B-18, found no differences in disease-free survival (DFS) or overall survival (OS) based on the timing of chemotherapy relative to surgery in operable breast cancer patients but found that pathological complete response (pCR) correlated with DFS and OS
Our study revealed a significant difference in rates of pCR achieved at a single institution over five years

Summary

Introduction

Neoadjuvant chemotherapy (NACT) was initially developed as a component of combined modality treatment for locally advanced breast cancer (LABC) that either was inoperable at presentation or required extended radical surgery [1]. The landmark trial, National Surgical Adjuvant Breast Project (NSABP) B-18, found no differences in disease-free survival (DFS) or overall survival (OS) based on the timing of chemotherapy relative to surgery in operable breast cancer patients but found that pCR correlated with DFS and OS. Following this trial, NAC was used to increase the rate of breast conserving surgery. Obtaining a pCR after neoadjuvant chemotherapy appears to have the strongest association with survival for patients with either HER2 overexpressed tumors or triple negative breast cancer (TNBC). A large meta-analysis of 12 international neoadjuvant clinical trials confirmed improved survival, among patients with TNBC and human epidermal growth factor receptor 2 (HER2) positive subtypes [7]

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Conclusion