Abstract PS5-12-29: Fertility Outcomes In Young Breast Cancer Patients And Their Prognosis And Offspring Health

Abstract Background: Most young breast cancer patients (≤40 years old) are in the golden period of fertility, but chemotherapy is prone to premature ovarian failure, and radiotherapy and long-term endocrine therapy further compress the fertility window. In addition, in response to the current controversy over fertility behavior on patient prognosis and the research gap in the long-term health of offspring with anti-tumor therapy, we designed this retrospective cohort study to clarify the fertility status of young breast cancer patients, verify the independent impact of fertility behavior on the prognosis of patients with different molecular types, and evaluate the association between treatment regimens and offspring health. Methods: This was a multicenter retrospective study on fertility outcomes and their prognosis and offspring health in young breast cancer patients. Based on the breast cancer database, we registered the baseline data of young breast cancer patients (≤40 years old), including age at initial diagnosis, molecular typing, tumor stage, treatment plan, fertility protection measures, etc., and followed up by telephone/email and other means to collect their fertility status, recurrence and offspring growth and development data. The primary endpoints were the disease-free survival (DFS), overall survival (OS) after childbirth and childrens’ growth and development. The secondary endpoints were the patient's fertility live birth rate, pregnancy outcomes and complications, use of fertility preservation techniques, breastfeeding status, etc. We used the Kaplan-Meier method to draw the survival curve of the patients after childbirth, and analyzed the growth trajectory of the offspring born after diagnosis by the Lambda-Mu-Sigma method, and plotted the growth and development curve. We used Log-rank to test the significance of differences in pregnancy rates between variables. We used Univariate Cox regression analysis to screen factors related to prognosis, and then used multivariate Cox regression analysis to adjust for potential confounding factors to clarify independent prognostic indicators of disease. Finally, descriptive analyses were performed for other secondary outcomes. Citation Format: A. Yuan, Z. Hu, C. Zheng, Z. Zheng, W. Liang, Y. Yuan, W. Wang, C. Zhang, Y. Pan, Y. Zhang. Fertility Outcomes In Young Breast Cancer Patients And Their Prognosis And Offspring Health [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS5-12-29.