Clinical treatment score Post-5 Years (CTS5) predicts the benefit of postmastectomy radiotherapy in patients with T1-2N1 luminal breast cancer

Ke Liu; Guan-Qiao Li; Si-Qi Li; Xue-Qin Chen; San-Gang Wu

doi:10.1016/j.breast.2025.103873

Clinical treatment score Post-5 Years (CTS5) predicts the benefit of postmastectomy radiotherapy in patients with T1-2N1 luminal breast cancer

Breast. 2025 Jan 2:79:103873. doi: 10.1016/j.breast.2025.103873. Online ahead of print.

Authors

Ke Liu¹, Guan-Qiao Li², Si-Qi Li², Xue-Qin Chen³, San-Gang Wu⁴

Affiliations

¹ Xiamen Key Laboratory of Clinical Efficacy and Evidence Studies of Traditional Chinese Medicine, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
² Department of Breast Surgery, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, China.
³ Xiamen Key Laboratory of Clinical Efficacy and Evidence Studies of Traditional Chinese Medicine, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China. Electronic address: xqchen@xmu.edu.cn.
⁴ Department of Radiation Oncology, Xiamen Cancer Quality Control Center, Xiamen Cancer Center, Xiamen Key Laboratory of Radiation Oncology, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China. Electronic address: wusg@xmu.edu.cn.

PMID: 39754792
DOI: 10.1016/j.breast.2025.103873

Abstract

Purpose: To investigate the clinical value of Clinical Treatment Score Post-5 Years (CTS5) to predict the survival benefits of postmastectomy radiotherapy (PMRT) of patients with T1-2N1 luminal breast cancer (BC).

Methods: Patients who were diagnosed with T1-2N1 luminal BC between 2010 and 2015 were included in the Surveillance, Epidemiology, and End Results database. The chi-square test, binomial logistic regression, Kaplan-Meier analysis, and multivariable Cox proportional hazard model were used for statistical analyses.

Results: A total of 11190 patients were included with a median follow-up time of 76 months. Regarding the CTS5 classification, 1641 (14.7 %), 3915 (35.0 %), and 5633 (50.3 %) patients had low-risk, intermediate-risk, and high-risk diseases, respectively. Patients with younger age, T2 stage, higher tumor grade, a higher number of positive lymph nodes, infiltrating lobular carcinoma subtype, and receipt of chemotherapy were associated with the receipt of PMRT (all P < 0.05). The multivariate analysis showed that the receipt of PMRT was the independent prognostic factor associated with better BCSS (P = 0.005) and OS (P < 0.001). The sensitivity analysis showed that PMRT did not improve BCSS (low-risk, P = 0.932; intermediate-risk, P = 0.952) and OS (low-risk, P = 0.637; intermediate-risk, P = 0.825) compared to those without PMRT in the low-risk and intermediate-risk groups. However, PMRT improved BCSS (P = 0.003) and OS (P < 0.001) in those with high-risk groups compared to those without PMRT.

Conclusions: CTS5 is an innovative model that could predict the survival benefit of PMRT for T1-2N1 luminal BC patients.

Keywords: Breast cancer; CTS5; Mastectomy; Prognosis; Radiotherapy.