Study Background
In breast cancer management, the proliferation marker Ki-67 has long been utilized to understand tumor biology and guide treatment decisions. Despite its widespread use in initial tumor characterization, the prognostic relevance of changes in Ki-67 levels during neoadjuvant chemotherapy (NACT) remains inadequately defined. Given that NACT aims to reduce tumor burden and improve surgical outcomes, understanding how Ki-67 dynamics reflect tumor response could refine risk stratification and treatment tailoring. This study addresses this unmet need by analyzing Ki-67 changes and their association with long-term outcomes.


