Taxane/anthracycline combinations reduced incidence of breast cancer recurrence in young women across molecular subtypes: a real-world evidence of Taiwan from 2011 to 2019

Purpose: Adolescent and young adult (AYA) patients with breast cancer generally have poor prognoses and a higher risk of secondary cancers compared to those at the same cancer stage. Notably, AYA patients in Asia exhibit a higher incidence rate of breast cancer, with Luminal A as the predominant molecular subtype, which contrasts with the trends observed in Western countries. This study aims to compare the efficacy of Taxane/Anthracycline combination-based regimens (TACB) versus Anthracycline-based regimens (AB) in AYA patients with stage I-II breast cancer, focusing on different molecular subtypes. Methods: This study utilized data from the Taiwan National Health Insurance Research Database (NHIRD) and the Taiwan Cancer Registry (TCR) from 2011 to 2019. The study cohort included patients aged 15 to 39 years who were diagnosed with stage I-II breast cancer and received either TACB or AB regimens. Propensity score matching and Cox proportional hazards regression models were used to calculate the hazard ratios (HR) for recurrence. Results: The results showed that TACB regimens significantly reduced the risk of recurrence compared to AB regimens across all patients (aHR 0.73, 95% CI 0.55–0.97). Specifically, for low/middle-recurrence risk groups, the aHR was 0.68 (95% CI 0.49–0.96), and for high-recurrence risk groups, it was 0.43 (95% CI 0.21–0.87). The analysis further indicated no significant differences in recurrence risk between AYA and non-AYA patients using TACB regimens. Conclusion: The TACB regimens showed a more favorable prognosis than AB regimens across all molecular subtypes. Furthermore, TACB regimens not only outperformed AB treatments but also closed the gap in prognostic outcomes between AYA and non-AYA patients. We believe the findings of this study are highly reliable and can provide valuable guidance for physicians in choosing the most appropriate treatment strategies for AYA patients with stage I-II breast cancer. Graphical abstract: (Figure presented.)