Serum PSA Levels and VDR Gene-Environment Interaction in Sudanese Men with Prostate Cancer: Role of BsmI Polymorphism (rs1544410)

Abstract

Background: BsmI is a 3'UTR VDR variant that may affect mRNA stability. Its association with prostate cancer (PCa) has been inconsistent across ethnic groups. Objective: The study aims to evaluate the association of the BsmI genotype and alleles with PCa risk and PSA levels in Sudanese men, a population with high ultraviolet exposure but endemic vitamin D insufficiency. Methods: This case-control study included 100 histologically confirmed PCa cases and 100 age-matched controls recruited from Kosti Teaching Hospital, the Kosti Oncology Centre, and Rabak Teaching Hospital in White Nile State between 2022 and 2025. Serum PSA was measured by immunoassay (Finecare). BsmI genotyping was performed by PCR-RFLP using NEB Buffer 3.1 at 65°C. Statistical analyses were conducted using SPSS version 26, with odds ratios (ORs) and 95% confidence intervals (CIs). Results: Mean PSA was higher in cases than in controls [15.2 ± 12.8 vs 2.1 ± 1.8 ng/mL, p < 0.001]. The BsmI genotype distribution did not differ between cases and controls (p = 0.12). However, the A allele was significantly more frequent in cases (42%) than in controls (30%, p = 0.001). The AA genotype had the highest PSA level in cases (20.1 ng/mL, p < 0.05) and controls (2.8 ± 1.9 ng/mL). Hardy-Weinberg equilibrium was reported in the controls (p = 0.45). Conclusion: The BsmI genotype was not associated with PCa risk in this sample; however, the A allele was more frequent in cases, and the AA genotype was associated with higher PSA levels. These findings suggest a possible relationship between BsmI and PSA, but the proposed influence of vitamin D insufficiency requires direct assessment in future studies.