Tissue Factor Pathway Inhibitor Gene Polymorphism -33T → C Predicts Improved Disease-Free Survival in Colorectal Cancer.

BACKGROUND

Tissue factor pathway inhibitor (TFPI) is an anticoagulant with antimetastatic properties. The homozygous CC polymorphism of TFPI (-33T → C) is associated with higher TFPI levels and lower venous thromboembolism risk. This study was the first to evaluate the impact of this polymorphism on disease-free survival (DFS) in cancer patients after curative resection.

METHODS

A prospectively maintained tumor bank with clinical data was used to identify patients who underwent curative surgery for colorectal cancer between 1994 and 2006. Germline DNA was extracted from formalin-fixed, paraffin-embedded normal colonic mucosa. Single nucleotide polymorphisms for TFPI (-33T → C), factor V Leiden (G1691A), and prothrombin (G20210A) were determined by polymerase chain reaction. Survival analysis was described using the Kaplan-Meier method. Multivariable regression analysis was performed using the Cox proportional hazard model.

RESULTS

Of the 127 patients identified, the CC genotype was found in 11 %. Venous thromboembolism incidence was 18 % in the TT/TC (wild type/heterozygous) genotypes and 7 % in the CC genotype (p = 0.46). The CC genotype was associated with superior DFS (hazard ratio 0.34, 95 % confidence interval 0.14-0.84; p = 0.02) with 5-year DFS of 63 vs. 24 % for CC vs. TT/TC, respectively. In multivariate analysis, CC polymorphism (hazard ratio 0.28, p = 0.008) was independently associated with improved DFS. The prevalence of factor V Leiden (0.8 %) and prothrombin (1.6 %) polymorphisms was too low to detect interaction with TFPI polymorphism or DFS.

CONCLUSIONS

These findings indicate that the inherited anticoagulant homozygous -33T → C TFPI polymorphism may protect against colon cancer recurrence and suggests a mediating role for the coagulation system in cancer outcomes.