Abstract
BACKGROUND: The response to chemotherapy in TNBC varies greatly, highlighting the need for predictive factors to estimate the success of the therapy. OBJECTIVE: The primary aim of this study is to analyze the relationship between Ki67 expression and clinicopathological features with chemotherapy response in locally advanced TNBC. METHODS: This retrospective study utilized secondary data from the medical records of locally advanced TNBC patients at Haji Adam Malik General Hospital, Medan. Out of an initial sample of 50 patients, 35 met the inclusion criteria, which required a confirmed TNBC diagnosis through histopathological and immunohistochemical examination, as well as complete clinical data. Chemotherapy response was assessed based on the World Health Organization (WHO) criteria, ensuring a standardized evaluation of treatment outcomes. RESULTS: The majority of patients were aged ≥50 years (54.5%), with a dominant tumor size of 2-5 cm (69.7%) and high histological grading (Grade 3: 60.6%). A total of 45.5% of patients exhibited high Ki67 expression (≥30%). Chemotherapy response was categorized as complete response (12.1%), partial response (45.5%), stable disease (30.3%), and progressive disease (12.1%). Statistical analysis revealed a significant relationship between Ki67 expression and chemotherapy response (p=0.02), with patients exhibiting high Ki67 expression more frequently achieving complete or partial response. CONCLUSION: High Ki67 expression is a critical indicator for predicting chemotherapy response in TNBC. Integrating Ki67 assessment with other clinicopathological factors is highly recommended to enhance predictive accuracy and optimize therapeutic planning for more effective treatment outcomes.