title: Factor V 1691 G-A (Leiden) polymorphism and cancer-related venous thromboembolism: a meta-analysis of published studies.
abstract: OBJECTIVE
  Although one of the most common genetic polymorphisms that predispose to venous thromboembolism (VTE) is factor V 1691 G-A (Factor V Leiden; FVL), the effect of this polymorphism on the development of VTE in cancer patients is unclear. We have therefore performed a meta-analysis to estimate the risk of VTE associated with FVL among cancer patients.
  
  
  METHODS
  Relevant studies published before May 2006 were retrieved from Pubmed/Medline. We selected studies comparing the prevalence of FVL in cancer patients with VTE with cancer patients without VTE. Both fixed and random effect models were used. P-values and odds ratios (ORs) with 95% confidence intervals (95% CI) were calculated by Fisher's exact test.
  
  
  RESULTS
  Pooled results from 9 studies, comprising 397 cancer patients with VTE and 678 cancer patients without VTE revealed that the prevalence of FVL was higher among cancer patients with VTE (7.3%) than those without VTE (4.6%) (chi(2) = 34.633 > chi(2) (18; 0.05) =28.869) (p=0.013). It was also found that mean effect size of FVL was 0.22 (95% CI 0.051-0.4892). Using the homogeneity test, there was evidence of statistical heterogeneity (Q(hom)= 46.334> chi(2) (8; 0.05) =15.507) (p=0.0000).
  
  
  CONCLUSIONS
  Although the published studies were small and the meta-analysis demonstrated an association of FVL with cancer-related thrombosis, testing for FVL can be routinely used as part of clinical thrombophilia assessment in cancer patients from the regions with high incidence of FVL.
authors.affiliation: Department of General Surgery and Surgical Oncology, Numune State Hospital, Konya, Turkey. aydaneroglu@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Eroglu
authors.forename: D
authors.initials: D
authors.lastname: Sertkaya Karasoy
authors.forename: N
authors.initials: N
authors.lastname: Eroglu
authors.forename: N
authors.initials: N
authors.lastname: Akar
mesh_terms: D005165:Factor V / Q000235:genetics*; D006801:Humans; D009369:Neoplasms / Q000150:complications*; D011110:Polymorphism, Genetic; D054556:Venous Thromboembolism / Q000235:genetics*
chemical_list: C095381:factor V Leiden; D005165:Factor V