Abstract PS6-53: Higher clinical lymph node stage predicts worse survival in patients with breast cancer who achieve a pathologic complete response after neoadjuvant chemotherapy

Abstract

Abstract Background: Despite patients with breast cancer who achieve a pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) generally demonstrate improved survival, some of these patients will develop breast cancer recurrence. Identification of factors associated with recurrence in patients with pCR after NAC would be helpful to optimize treatment strategies in breast cancer. In this study, we aim to particularly explore the factors associated with the prognosis of this patient population.Methods: Data of patients from three tertiary hospitals and treated with NAC between 2005 and 2019 were retrospectively collected. A pCR was defined as no invasive tumor in the breast and no tumor in the lymph node (ypT0/is, ypN0). Factors associated with pCR were analyzed using univariable and multivariable logistic regression analyses. Disease-free survival (DFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. The prognostic value of clinicopathological factors regarding DFS and OS were determined by univariable and multivariable Cox regression analyses.Results: A total of 897 patients were used for the analysis, including 287 patients with a pCR and 610 patients without pCR. Clinical TNM stage, histological grade, estrogen receptor (ER) status, progesterone receptor (PR) status, human epidermal growth factor receptor 2 (HER2) status, Ki67, molecular subtype, NAC regimen and NAC cycles were associated with pCR status, with TNM stage and molecular subtype as independent predictors of pCR. Patients with a pCR had a superior DFS (pCR vs non-pCR, hazard ratio [HR] 0.26 (95% confidence interval [CI] 0.15-0.45, P<0.001) and OS (pCR vs non-pCR, hazard ratio [HR] 0.13 (95% confidence interval [CI] 0.05-0.35, P<0.001). In patients with pCR, clinical T stage, N stage and TNM stage were associated with DFS and OS, with higher N stage as an independent predictor of a worse DFS and OS.Conclusions:Clinical N stage of breast cancer is an independent predictor of worse DFS and OS in patients with a pCR after NAC. Possible this could support treatment escalation in this patient population in the future. Citation Format: Li-Yun Xie, Kun Wang, Yan-Xia Shi, Hai-Lu Chen, Jian-Hao Huang, Yang-Hang Fan, Si-Qi Qiu, Zhi-Yong Wu. Higher clinical lymph node stage predicts worse survival in patients with breast cancer who achieve a pathologic complete response after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS6-53.