RÉSUMÉ
Objective:To analyze the relationship between gene polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and plasminogen activator inhibitor-1 (PAI-1) and lower limb deep venous thrombosis (DVT) after colorectal cancer surgery.Methods:The clinical data of patients with colorectal cancer who underwent surgical treatment in Zhangjiakou First Hospital from February 2020 to February 2023 were analyzed retrospectively. According to the presence or absence of lower limb DVT after surgery, the patients were divided into DVT group (20 cases) and non-DVT group (80 cases). The polymorphism of MTHFR C677T and PAI-1 promoter 4G/5G were detected by polymerase chain reaction method. The relationship between the polymorphisms of MTHFR C677T and PAI-1 promoter 4G/5G and lower limb DVT after colorectal cancer surgery was discussed by logistic regression analysis.Results:TT genotype frequency and T allele frequency of MTHFR C677T in the DVT group were higher than those in the non-DVT group: 65.00% (13/20) vs. 25.00% (20/80), 80.00% (32/40) vs. 38.75% (62/160). CC genotype frequency and C allele frequency were lower than those in the non-DVT group: 5.00% (1/20) vs. 47.50% (38/80), 20.00% (8/40) vs. 61.25% (98/160), with statistically significant differences ( P<0.05). There was no significant difference in CT genotype frequency between the two groups ( P>0.05). 4G/4G gene frequency and 4G allele frequency of PAI-1 gene in the DVT group were higher than those in the non-DVT group: 50.00% (10/20) vs. 21.25% (17/80), 67.50% (27/40) vs. 38.75% (62/160). 5G/5G gene frequency and 5G allele frequency were lower than those in the non-DVT group: 15.00% (3/20) vs. 43.75% (35/80), 32.50% (13/40) vs. 61.25% (98/160), with statistically significant differences ( P<0.05). There was no significant difference in 4G/5G gene frequency between the two groups ( P>0.05). The distribution frequency of TT genotype of MTHFR C677T and 4G/4G genotype of PAI-1 promoter in DVT group was higher than that in non-DVT group: 55.00% (11/20) vs. 22.50% (18/80), with a statistically significant difference ( P<0.05). Multivariate Logistic regression analysis showed that MTHFR C677T TT genotype ( OR = 1.499, 95% CI 1.201 to 1.871), PAI-1 promoter 4G/4G genotype ( OR = 1.471, 95% CI 1.170 to 1.850) and MTHFR The C677T loci TT genotype combined with the 4G/4G genotype of the PAI-1 promoter ( OR = 1.592, 95% CI 1.258 to 2.014) were risk factors for lower limb DVT after colorectal cancer surgery ( P<0.05). Conclusions:The TT genotype of MTHFR C677T site and the 4G/4G genotype of PAI-1 promoter are closely related to the formation of lower limb DVT after colorectal cancer surgery, and the risk of lower limb DVT is higher in patients with both genotype TT and 4G/4G.