Significance of a preoperative tumor marker gradient for predicting microvascular invasion in cases of hepatocellular carcinoma

Although vascular invasion is an important factor in the progression and treatment of hepatocellular carcinoma (HCC), it remains difficult to determine, on the basis of preoperative imaging alone, whether vascular invasion, especially microvascular invasion, has occurred. The current retrospec-tive study enrolled 292 patients who, between 2004 and 2014, underwent curative hepatectomy as an initial treatment for HCC. The patients were divided between those with (n=70) and those without (n=222) microvascular invasion. Whether tumor-marker-based prediction of microvascular invasion was possible was assessed by comparing the preoperative serum α-fetoprotein (AFP) and prothrombin induced by vitamin K absence or antagonist-II concentrations between two groups of patients. The AFP concentration was significantly higher in patients with microvascular invasion compared with patients without microvascular invasion (P=0.0019). Stepwise logistic regression analysis demonstrated the AFP concentration and the logarithmic conversion ratio of the AFP gradient (log AFP grad) to be useful (P=0.0019; 0.0424) for predicting micro-vascular invasion. The serum AFP concentration and log AFP grad appear to be clinically useful in predicting microvascular invasion in patients with HCC.