Vitamin K2 Has No Preventive Effect on Recurrence of Hepatocellular Carcinoma after Effective Treatment

Hepatocellular carcinoma (HCC) has a poor prognosis because of its high recurrence rate. Recently, vitamin K2 has been reported to inhibit the growth of HCC cell lines. To clarify the preventive effect of vitamin K2 on HCC recurrence, we studied 72 HCC patients who had been treated with surgical resection, local ablation or transarterial embolization: their etiologies were hepatitis B virus (n = 21), hepatitis C virus (n = 47), both B and C viruses (n = 2) and non-B or non-C virus (n = 2). We divided them into 2 groups: in one group, patients were treated with 45-mg/day vitamin K2 [K2-treated group (n = 23)], and in another, patients were not given vitamin K2 or a placebo [non-treated control group (n = 49)]. The obtained results between the 2 groups were compared. HCC recurred in 12 (52.2%) of the 23 K2-treated patients, and 22 (44.9%) of the 49 control patients. The differences in cumulative recurrence-free rate and cumulative survival rate between both groups were not significant (P = 0.92 and P = 0.08, respectively). As observed, chemopreventive effects of vitamin K2 at a clinically relevant dose on HCC recurrence were ineffective after effective treatment for HCC. Different regimens such as higher doses of vitamin K2 or combination therapy with other drugs may be worth testing to further explore the preventive effect on HCC recurrence.