Serum Vitamin D status and VDR (FokI) polymorphism association study in Pakistani females with breast cancer

Background: Breast cancer is most common in Pakistani women at young age compared to West where it is most common after 60 years of age. Variations in genes controlling vitamin D activity would play a role in determining the risk of breast cancer in women at early age. Purpose: To determine the association of vitamin D receptors (VDR) gene polymorphisms (FokI) with breast cancer risk in Pakistani women. Methods: FokI polymorphisms were studied through the polymerase chain reaction-restriction fragment length polymorphism technique on blood samples of 300 breast cancer and 300 healthy women. Results: This study found that circulating level of 25(OH)D3 was significantly lower among breast cancer patients as well as healthy subjects. Patients with large tumor size had significantly lower vitamin D levels. VDR FokI genotypes were significantly distributed (P ≤ 0.00001) in Pakistani women with newly diagnosed breast cancer. A significant association between different FokI genotypes and circulating levels of 25(OH)D3 was found. Patients with FF genotype was significantly (P < 0.0001) associated with higher risk of breast cancer (OR 8.9, 95% CI 0.17-0.45) compared to Ff and ff genotype. Conclusion: VDR gene FokI polymorphism was associated with plasma vitamin D level and significant differences found in mean serum vitamin D levels between genotype groups of FokI. The study concluded that FokI might be one of the contributors to increase relative risk of breast cancer in Pakistani women.