Financial Toxicity in Patients With Breast Cancer Treated at Private Medicine Institutions in Brazil.

Financial toxicity (FT) refers to the negative impact of the financial burden of cancer diagnosis and treatment on patients' well-being. With rising global costs of oncologic therapies, diagnostics, and supportive care, FT has become a key concern in cancer care, influencing adherence, quality of life, and outcomes. Breast cancer, given its high prevalence and socioeconomic implications, is notably associated with FT. Beyond direct medical expenses, patients often face income loss and out-of-pocket costs for supportive care, which can significantly affect their therapeutic trajectory. Addressing FT is thus essential to ensure equitable cancer care. A 34-item questionnaire, including the Comprehensive Score for Financial Toxicity (COST) tool, was administered to breast cancer patients treated at three private institutions in Brazil. Data were analyzed using descriptive statistics, linear regression, and ANOVA (p ≤ 0.05). Among 912 participants 85.1% self-identified as White. Most were married or in a stable union (67.8%), and 50.9% held a postgraduate degree. A majority (84.2%) had early-stage disease, 54.6% had been diagnosed within 2 years prior to the study, and 92.1% reported having health insurance. Despite this, 36.6% experienced a reduction in their standard of living following treatment, and 15.6% reported having to sell assets or property. The mean COST score was 24.2 (SD = 8.6; median = 25.0). Factors significantly associated with greater financial toxicity (lower COST scores) included age below 40 years, lack of health insurance, unemployment or medical leave, and household income below 10,000 BRL per month. These findings highlight the considerable financial burden experienced by breast cancer patients, even in the private healthcare system, and underscore the need for strategies to mitigate FT in oncology care.