The 19-bp deletion of dihydrofolate reductase (DHFR), methylenetetrahydrofolate reductase (MTHFR) C677T, Factor V Leiden, prothrombin G20210A polymorphisms in cancer patients with and without thrombosis.

Venous thromboembolism (VTE) is a common complication in cancer patients. Several genetic risk factors related to thrombophilia are known; however, their contributions to thrombotic tendency in cancer patients have conflicting results. In the present study, we have focused on the prevalence of methylenetetrahydrofolate reductase (MTHFR) C677T, dihydrofolate reductase (DHFR) 19-bp deletion within intron 1, factor V Leiden (FVL), and prothrombin (PT) G20210A polymorphisms in cancer patients with and without VTE. The study consisted of 63 cancer patients with VTE (group 1) and 124 cancer patients who had no evidence of VTE (group 2). Four gene polymorphisms were determined by the method of polymerase-chain-reaction-based DNA analysis. The prevalence of DHFR 19-bp deletion and MTHFR C677T polymorphisms was similar in two groups (p > 0.05). The frequency of FVL was significantly higher in group1 compared with group 2 (31.7% vs. 1.6%, p < 0.0001), but PT G20210A polymorphism was not associated with VTE. Cancer patients with thrombosis should be evaluated for FVL, but routine screening for PT G20210A, MTHFR C677T and DHFR 19-bp deletion polymorphisms is not suggested.