title: Postoperative use of the chemopreventive vitamin K2 analog in patients with hepatocellular carcinoma.
abstract: OBJECTIVE
  To evaluate the chemopreventive efficacy of vitamin K2 (VK2) analog in patients with hepatocellular carcinoma (HCC) after curative hepatic resection or local ablation, since a recent randomized control trial (RCT) and systematic review have given contradictory results.
  
  
  METHODS
  MEDLINE, EMBASE and Cochrane library databases were systematically searched through the end of May 2012. Meta-analysis of RCTs and cohort studies was performed to estimate the effects of the VK2 analog on tumor recurrence rate and overall survival (OS). Risk ratios (RRs) and 95% confidence intervals (95% CIs) were calculated.
  
  
  RESULTS
  Six RCTs and one cohort study involving a total of 930 patients were included. VK2 analog therapy did not reduce the 1-year recurrence rate, with a pooled RR of 0.67 (95% CI 0.39-1.13, p = 0.13). However, VK2 analog therapy was associated with a significant reduction in the 2- and 3-year tumor recurrence rates, with respective pooled RRs of 0.65 (95% CI 0.51-0.83, p<0.001) and 0.70 (95% CI = 0.58-0.85, p<0.001). The therapy was also associated with a significant improvement in 1-, 2-, and 3-year OS, with respective pooled RRs of 1.03 (95% CI 1.01-1.05, p = 0.02), 1.11 (95% CI 1.03-1.19, p = 0.005) and 1.14 (95% CI 1.02-1.28, p = 0.02). None of the studies reported adverse effects attributable to VK2 analog therapy.
  
  
  CONCLUSIONS
  The VK2 analog may reduce recurrence rate after 1 year and improve OS in HCC patients as early as 1 year. However, these findings should be considered preliminary since the majority of patients came from an RCT with survival data out to only 1 year. More extensive studies with larger sample sizes and longer follow-up are needed.
authors.affiliation: Hepatobiliary Surgery Department, Tumor Hospital of Guangxi Medical University, Nanning, People's Republic of China.
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Zhong
authors.forename: Xin-Shao
authors.initials: XS
authors.lastname: Mo
authors.forename: Bang-De
authors.initials: BD
authors.lastname: Xiang
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Yuan
authors.forename: Jin-Fang
authors.initials: JF
authors.lastname: Jiang
authors.forename: Gui-Sheng
authors.initials: GS
authors.lastname: Xie
authors.forename: Le-Qun
authors.initials: LQ
authors.lastname: Li
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery; D018890:Chemoprevention; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery; D011182:Postoperative Care; D017594:Publication Bias; D012008:Recurrence; D012306:Risk; D016896:Treatment Outcome; D024482:Vitamin K 2 / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use*
chemical_list: D024482:Vitamin K 2