Soluble VEGF receptor-2 may be a predictive marker of anti-angiogenic therapy with clinically available safe agents.

The identification of biomarkers of anti-angiogenic therapy that predict clinical benefit is of vital importance. We previously reported that a combination treatment with clinically available safe agents, specifically angiotensin-converting enzyme inhibitor (ACE-I) and vitamin K (VK), inhibited the cumulative recurrence of hepatocellular carcinoma (HCC) via suppression of the vascular endothelial growth factor (VEGF). The present study aimed to identify non-invasive biological markers that predict the clinically beneficial effect of this combination regimen. A combination of ACE-I (perindopril; 4 mg/day) and VK (menatetrenone; 45 mg/day) was administered for 54 months following curative therapy for HCC. The cumulative recurrence and several indices, which are reportedly considered as biological markers of anti-angiogenic therapies, were analyzed. The combined treatment of ACE-I and VK markedly inhibited the cumulative recurrence of HCC during the 54-month follow-up. The serum VEGF and soluble VEGF receptor (sVEGFR)-2 were significantly suppressed with this combination regimen, whereas sVEGFR-1 was not. In HCC patients without recurrence, a significant suppression of VEGF and sVEGFR-2 was achieved within 6 and 3 months after treatment, respectively. In conclusion, the combination treatment of ACE-I and VK is a potentially novel anti-angiogenic strategy for secondary chemoprevention against HCC since the two agents are widely used in clinical practice without serious side effects. Furthermore, sVEGFR-2 may become a useful clinical predictive marker of this combination treatment.