Survival Analysis of Triple Negative Breast Cancer Patients Based on Ki-67 Protein Expression in Prof. Dr. I.G.N.G Ngoerah General Hospital Denpasar

Abstract

Aim: To prove that 2-year mortality of triple-negative breast cancer (TNBC) patients with protein Ki-67 expression ≥ 40% is higher than patients with protein Ki-67 expression < 40% in Prof. dr. I.G.N.G. Ngoerah General Hospital Denpasar. Methods: This was a bidirectional cohort study with survival analysis. The end of follow-up was the mortality state (survived or deceased) of patients observed for 24 months (2 years) since the patient was diagnosed with TNBC. This study was conducted in the Surgical Oncology Department, Prof. dr. I.G.N.G. Ngoerah General Hospital Denpasar from January 2018 until January 2022. The sample was recruited by a consecutive sampling method. The Kaplan-Meier curve and log-rank test determined overall survival (OS) and its difference between the Ki-67 expression group. Multivariate analysis using Cox regression was also conducted. Results: 58 TNBC patients were included in this study. At the end of the study, 31 patients survived, with an OS of 53.4%. The mean OS time was 19 months (95%CI = 17.12-20.88). The two-year OS of TNBC patients with Ki-67 ≥ 40% group was 37.5%; meanwhile, in Ki-67 expression < 40% was 88.9%. It was statistically significant (p = 0.001). Multivariate analysis revealed that Ki-67 ≥ 40% expression was a significant and independent predictor factor for a high 2-year mortality rate (adjusted HR = 9.140; p = 0.008). Tumor-resection history also had a significant result in multivariate analysis (p < 0.05). Conclusion: TNBC patients with Ki-67 ≥ 40% have a higher 2-year mortality rate than patients with Ki-67 expression < 40%.