Assessment of SF3B1 Expression as a Prognostic Marker for Neoadjuvant Chemotherapy Response in Stage III Triple-Negative Breast Cancer.

BACKGROUND: SF3B1 is a splicing factor that plays a crucial role in cancer progression and is commonly found in various types of solid cancers. However, the reports regarding the clinical implications of SF3B1 in terms of therapy response, survival, and its relationship with patients' clinicopathological features are still limited. This study aimed to assess SF3B1 expression for neoadjuvant chemotherapy response in stage III triple-negative breast cancer. METHODS: This case-control study was conducted at Prof. Dr. I.G.N.G. Ngoerah General Hospital from March to October 2021. Stage III TNBC breast cancer patients who received neoadjuvant chemotherapy were included. Variables assessed included SF3B1 expression, NAC response, and various histological and clinical parameters. Immunohistochemistry (IHC) for SF3B1 expression was performed using the avidin-biotin method. Data analysis involved univariate, bivariate (chi-square), and multivariate (logistic regression) methods using SPSS, with significance set at p ≤ 0.05. RESULTS: Analysis showed that high Ki-67, tumor-infiltrating lymphocytes (TILs), and SF3B1 status significantly increased the risk of chemoresistance in TNBC breast cancer (OR=6.4, 95%CI=1.20-34.19, p-value=0.017; OR=4.8, 95%CI=1.05-21.75, p-value=0.031; OR=13.5, 95%CI=1.56-116.24, p-value=0.008, respectively) No significant relationships were found with age, grading, or menopausal status. Multivariate analysis confirmed these variables independently influenced chemoresistance, with aOR=14.4, 95%CI=1.80-115.73 for Ki-67 (p-value=0.012), aOR=6.7, 95%CI=1.12-40.46 for TIL (p-value=0.037), and aOR=13.714, 95%CI=1.56-116.24 for SF3B1 (p-value=0.018). CONCLUSIONS: High SF3B1 expression, alongside high Ki-67 and TIL levels, is potentially a prognostic marker for chemoresistance in stage III TNBC. These findings suggest that targeting SF3B1 could offer a novel therapeutic approach in TNBC patients.