Relationship Between Vitamin D Receptor TaqI Polymorphism and the Clinicopathological Features of Breast Cancer Patients at Sanglah Hospital, Denpasar, Bali

Introduction: Breast cancer is a malignant tumor of the mammary gland. Breast cancer is associated with vitamin D receptor (VDR) TaqI polymorphism. This study aims to prove the relationship between TaqI polymorphism and the clinicopathology of breast cancer in Bali. Methods: This study is an observational analytic study with a cross-sectional design conducted from February to August 2021. A total of 39 sample DNA isolates from breast cancer patients at Sanglah Hospital were enrolled in the study. The independent variable was the VDR TaqI gene polymorphism, while the dependent variable was the clinicopathological breast cancer (clinical stage and histological grading). The examination was carried out by PCR and sequencing. Clinical staging and histological grading of breast cancer were taken from the patient's medical record. The results were analyzed using descriptive and bivariate analysis. Results: TaqI polymorphism of breast cancer at Sanglah Hospital Denpasar was dominated by the wild type TT genotype as much as 59%. This study did not find the CC genotype. The results of the statistical analysis did not find a significant relationship (p>0.05) between TaqI polymorphisms with TT and TC genotypes and clinicopathology of breast cancer but found a significant relationship (p=0.047) with histological grading. The TT and TC genotypes were found to increase the risk of breast cancer severity by 3,810 compared to individuals without the TT and TC genotypes. Analysis of confounding variables with clinicopathological breast cancer found no significant relationship (p>0.05) between the age of diagnosis, menstrual status, and hormonal contraceptive use with the characteristics of the sample. Conclusion: It was concluded that breast cancer patients at Sanglah Hospital Bali had TaqI polymorphisms with TT and TC genotypes. TT and TC genotypes are associated with histological grading and can increase the severity of histological grading in breast cancer patients at Sanglah Hospital Denpasar Bali.