Abstract PO1-08-05: Using the CTS5 Score to Predict Late Recurrence in Male and Female Estrogen Receptor-Positive Breast Cancer Patients: a SEER database analysis of 65,729 cases

Abstract Purpose: The Clinical Treatment Score post-5 years (CTS5) score is a prognostic prediction tool to predict the risk of late distant recurrence in postmenopausal women with estrogen receptor-positive (ER+) breast cancer. Here we aimed to evaluate the prediction role of CTS5 in male breast cancer patients using the Surveillance, Epidemiology, and End Results (SEER) database. Methods: ER+ early male and female breast cancer patients from the SEER database 2010-2013 were included. Clinicopathological features and the CTS5 score between the gender groups were compared using chi-square test. Overall survival (OS) and breast cancer-specific survival (BCSS) were estimated by Kaplan-Meier plots and compared between the groups with Log-rank test and multivariate cox proportional hazard regression models was used to determine the relationship between the CTS5 score and breast cancer survival outcomes in different gender cohorts. Results: A total of 65,729 ER+ breast cancer patients were included in the study and 611 were men. Male breast cancer was more likely to be diagnosed later in life (50 years old, 87.1% vs 73.6%, p 0.001), with more aggressive biological features (grade Ⅱ 51.6% vs 47.2%, p 0.001; grade Ⅲ 37.8% vs 28.3%, p 0.001) , and higher tumor burden (stage Ⅱ 45.8% vs 32.9%, p 0.001, stage Ⅲ 17.5% vs 10.5%, p 0.001) when compared to female counterparts. More male patients were CTS5 intermediate- or high-risk than female patients (high 7.9% vs 6.3%, intermediate 41.1% vs 24.6%, low 51.1% vs 69.1%, p 0.001). Patients were divided into 0-5 year and 5 year cohorts based on whether they had a BCSS event within 5 years. In the 5 year cohort, patients with CTS5 high- or intermediate- risk had worse survival outcomes compared with low-risk cases in male and postmenopausal female patients but not in premenopausal female patients. In the 0-5 year cohort, the CTS5 score was not predictive for disease recurrence in male or postmenopausal patients. Conclusion: Male breast cancer patients were more likely to have aggressive tumors and worse survival outcomes. The CTS5 score could be applied to predict breast cancer-specific mortality risk beyond 5 years in male ER+ breast cancer patients. Citation Format: Fenhua Wang, Fang Ren, Jian Qian, Yunxia Xu, Jiayi Wu, Yu Zong, Xidong Gu. Using the CTS5 Score to Predict Late Recurrence in Male and Female Estrogen Receptor-Positive Breast Cancer Patients: a SEER database analysis of 65,729 cases abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-08-05.