Introduction: Systemic inflammation significantly influences breast cancer therapeutic efficacy; however, static baseline assessments often fail to capture dynamic treatment responses. Longitudinal monitoring of hematologic inflammatory indices may provide a more robust surrogate for real-time chemosensitivity. Therefore, this study investigates dynamic changes in inflammatory biomarkers during chemotherapy and evaluates their association with objective therapeutic response in breast cancer patients.

Material and methods: This descriptive cross-sectional study at Imam Reza Hospital (Tabriz) enrolled 125 participants via convenience sampling, determined using the Cochran formula. Investigators systematically extracted comprehensive demographic, clinical, laboratory, and histopathological data from medical records. Statistical analyses assessed variable associations, ensuring all procedures strictly adhered to institutional ethical guidelines and the Declaration of Helsinki.

Results: Baseline systemic inflammation inversely correlates with chemosensitivity (P < 0.001). Responders demonstrated significant downward kinetics, whereas non-responders maintained elevated inflammatory burdens throughout therapy. A multivariable combined predictive model significantly outperformed individual biomarkers (AUC 0.912, 95% CI 0.861 to 0.963, P < 0.001). These results identify on-treatment biomarker trajectories as robust, accessible surrogate indicators of clinical therapeutic efficacy and patient prognosis in breast cancer management.

Conclusion: Our data establish that systemic inflammatory indices function as powerful, non-invasive predictors of therapeutic response. Integrating longitudinal kinetics with baseline measurements allows clinicians to accurately stratify refractory cases and optimize personalized therapeutic strategies.