Time to treatment initiation for triple-negative breast cancer in Brazil: A call for public health action.

1544 Background: Timely initiation of treatment is a critical determinant of outcomes in breast cancer. In Brazil, national legislation mandates treatment beginning within 60 days of histopathological diagnosis. Adherence to this interval may be particularly relevant in triple-negative breast cancer (TNBC), an aggressive subtype associated with rapid disease progression and poor prognosis. Methods: Data were collected from patients (pts) diagnosed with primary TNBC, stages I-III, treated at two large public cancer centers in Brazil between 2010-2016 and in 2022 and one private oncology network in Brazil between 2020-2023. Treatment delay was defined as an interval ≥60 days. Data were compared between public and private settings. Logistic regression models were used to identify factors associated with treatment delay. Results: A total of 1,644 pts were included, 1,347 (82%) in the public and 297 (18%) in the private setting. Pts aged <50 years accounted for 40.3% of those in the public healthcare system and 67.7% of those in the private sector. Patients in the private setting presented with earlier-stage disease (49.5% diagnosed at stage I-IIA vs. 28.1% in the public setting), whereas a higher proportion of stage IIB-III disease was observed in the public setting (71.9% vs. 50.5%; P < 0.001). Treatment initiation beyond 60 days occurred in 75.4% of pts in the public setting, compared with 14.1% in the private setting (P < 0.001). In multivariable logistic regression analysis, factors independently associated with treatment delay included public healthcare service (OR 19.26, 95% CI 13.3–27.9; P < 0.001), older age compared to ≤30 ys, ranging from OR = 2.06 among patients aged 31–39 years (95% CI 1.02–4.16; p = 0.045) to OR = 5.48 among those aged ≥70 years (95% CI: 2.55–11.81; p < 0.001) and earlier stage (I–IIA vs. IIB-III OR = 1.45, 95% CI 1.10--1.91; p = 0.008). Conclusions: Rates of treatment initiation beyond 60 days after diagnosis are alarmingly high in the Brazilian public health system, indicating that the 60-day law implementation remains suboptimal. Lower odds of treatment delay among younger patients and those with more advanced disease likely reflect clinical prioritization of individuals with more aggressive or symptomatic presentations. These findings underscore the urgent need for health policy interventions aimed at reducing delays in cancer care, particularly for high-risk subtypes such as TNBC.