Overall Survival and Economic Impact of Triple-Negative Breast Cancer in Brazilian Public Health Care: A Real-World Study

PURPOSE Triple-negative breast cancer (TNBC) presents notable treatment difficulties, especially in the public health care systems of low- and middle-income countries where access to advanced therapies is restricted. This study investigates TNBC's clinical, epidemiologic, and economic effects on survival within Brazil's public health care system. METHODS We conducted a retrospective cohort study of patients with TNBC treated between 2010 and 2019. Overall survival (OS) rates by stage were analyzed across various patient groups, including those receiving neoadjuvant or adjuvant treatment, patients with or without complete pathologic response, Black and non-Black patients, and those treated with or without carboplatin-based therapy. Cox proportional hazards models were applied to estimate hazard ratios (HRs) with 95% CIs, and annual treatment costs were calculated per stage. RESULTS Among 1,266 patients with TNBC, 710 met eligibility criteria. Kaplan-Meier analysis indicated stage II patients had a 47% lower mortality risk than stage III (HR, 0.53 [95% CI, 0.33 to 0.85]; P = .009). Patients in the adjuvant treatment group had a reduced risk (HR, 0.48 [95% CI, 0.34 to 0.69]) compared with the neoadjuvant group. Achieving complete pathologic response (pCR) greatly improved OS (HR, 0.21 [95% CI, 0.11 to 0.43]; P < .001). Black patients had better survival rates than non-Black (HR, 0.58 [95% CI, 0.40 to 0.86]; P = .006). Carboplatin use did not significantly affect OS (HR, 0.96 [95% CI, 0.65 to 1.43]; P = .857). The average monthly cost for systemic TNBC treatment increased with disease progression, from $101.87 in US dollars (USD) for stage I to $314.77 USD for stage IV second-line therapy. CONCLUSION This study provides insight into TNBC in Brazil's public health system, showing that OS decreases with disease progression but is higher among Black patients. pCR and adjuvant therapy improve survival, although costs increase significantly at advanced stages, highlighting the economic burden of late-stage TNBC management.