Impact of the CPS-EG score as a new prognostic biomarker in triple-negative breast cancer patients who received neoadjuvant chemotherapy

Abstract

Background: This study aimed to establish risk groups on the basis of CPS-EG scores, independent of pCR status, in triple-negative breast cancer (TNBC) patients receiving neoadjuvant chemotherapy (NACT) to identify the prognostic impact of the CPS-EG score. Methods: Patient characteristics included age, menopausal status, clinical stage, pathological stage, estrogen receptor (ER) expression, nuclear grade, Ki-67 proliferation index, residual cancer burden (RCB) score, HER2 status, and other tumor characteristics. The CPS-EG scoring system included clinical stage, pathological stage, ER status, and grade. Patients were divided into two groups on the basis of their CPS-EG scores ≤ 3 and > 3. Results: A total of 148 patients who were diagnosed with TNBC and treated with NACT were included in the study. A total of 52.0% of the patients had a CPS-EG score of ≤ 3, whereas 48.0% had a score of > 3. The rate of patients who achieved pCR was 29.7% (n = 44). CPS-EG score (HR: 2.331; 95%CI; 1.179–4.608; p = 0.015), pCR (HR: 0.348; 95%CI; 0.144–0.844; p = 0.019), pre-treatment mKi-67 proliferation index (HR: 0.467; 95%CI; 0.251–0.871; p = 0.017), and RCB score (HR: 0.401; 95%CI; 0.174–0.923; p = 0.032) were identified as significant prognostic factors for 5-year DFS. For 5-year OS, significant prognostic factors were CPS-EG score (HR: 2.30; 95%CI; 1.036–4.799; p = 0.040) and pre-treatment mKi-67 proliferation index (HR: 0.484; 95%CI; 0.246–0.954; p = 0.036). Conclusions: The CPS-EG score, pre-treatment mKi-67 level, and the pCR and RCB score were practical prognostic markers for long-term survival. Conversely, the prognostic significance of pCR status was diminished, particularly in predicting OS. These findings underscore the importance of not only post-treatment pathological staging but also the initial tumor stage and biological characteristics of the tumor in predicting ultimate survival outcomes following neoadjuvant chemotherapy in TNBC patients.