Abstract PS1-02-09: Association between financial toxicity and mental health among metastatic breast cancer survivors

Abstract Background: Metastatic breast cancer (MBC) survivors require long-term treatment, resulting substantial costs and financial toxicity. Thought the financial burden was observed to be associated with cancer survivors’ clinical outcome, limited evidence focused on the toxicity on mental health. Here, we aimed to determine the association between financial toxicity and mental health and its mediators among MBC survivors. Methods: Female MBC patients diagnosed in our institution during May 2023 to October 2023 were included. Financial toxicity was assessed using Comprehensive score for financial toxicity based on the patient-reported outcome measures (COST-PROM) instrument. Mental health status was profiled through Connor-Davidson Resilience Scale (CD-RISC). To further explore the modifiable psychological symptoms, the Cancer Loneliness Scale (CLS), Cancer-related Negative Social Expectations Scale (CRNSES), M. D. Anderson Symptom Inventory (MDASI) and Perceived Social Support Scale (PSSS) were adopted to characterize loneliness, social expectations, oncology symptom awareness, and social support, respectively. The association between financial toxicity and mental health status was determined using conditional linear regression, adjusted for demographic factors, disease characteristics, treatment, and socioeconomic status. Mediation analysis with structural equation modeling (SEM) was performed to explore the mediator of the association. Further, we conducted the network analysis to profile the correlation among identified mediators, including a binary variable that encoded whether survivor was of financial toxicity. A two-tailed P 0. 05 was considered as statistically significant. Results: A total of 226 MBC survivors were included, of whom the median age were 55 (interquartile range 45 to 64 years) years, and 173 (76. 5%) were with financial toxicity. Financial toxicity was significantly associated with mental health after adjusted for demographic factors, disease characteristics, treatment, and socioeconomic status (coefficient, 0. 197, 95% CI, 0. 024 to 0. 370). CLS, CRNSES, MDASI-part 2, and PSSS were identified as the mediators (indirect effect 95% CI, CLS 0. 087 0. 04 to 0. 134, CRNSES 0. 045 0. 009 to 0. 08, MDASI-part2 0. 071 0. 027 to 0. 115, and PSSS 0. 043 0. 008 to 0. 078, all P 0. 05), which corresponding to 72. 7%, 37. 1%, 59. 2%, and 35. 9% of the relative effect, respectively. The network analysis showed that “relations (MDASI-2₄) ”, “social discomfort (CRNSES₁) ”, and “felt empty (CLS₆) ” were the mental health nodes with the top 3 largest strength (mean SD of bootstrapped standardized index value, 1. 79 0. 69 for “relations”, 1. 71 0. 85 for “social discomfort”, and 1. 57 0. 99 for “felt empty”, respectively), while the “felt empty (CLS₆) ” and “perceived avoidance (CRNSES₂) ” were the node with largest betweenness and closeness (mean SD of bootstrapped standardized index value, 2. 12 3. 4 for “felt empty and 1. 36 2. 40 for “perceived avoidance”), respectively. Conclusion: Financial toxicity was significantly associated with worse mental health. Targeting certain dimensions regarding loneliness, social expectations, oncology symptom awareness, and social support might could reverse the toxicity. Citation Format: Z. Xu, Y. Lu, Y. Wu, H. Shi, C. Shangguan, K. Shen, Q. Qu, N. Zhang. Association between financial toxicity and mental health among metastatic breast cancer survivors 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 PS1-02-09.