Microvascular invasion (MVI) is an aggressive behavior of hepatocellular carcinoma (HCC) that being an independent predictor of tumor recurrence after hepatectomy or liver transplantation. Preoperative prediction of MVI has important clinical significance.

To use non-invasive imaging and serological indicators to construct a nomogram for predicting MVI in order to provide a clinical reference.

The relevant clinical data of 284 patients who underwent radical resection of HCC in the Second Affiliated Hospital of Kunming Medical University from 2016 to 2021 were retrospectively analyzed, and HCC patients admitted from 2016 to 2020 were categorized as the model group (n=208) according to the admission time, and HCC patients admitted in 2021 were categorized as the validation group (n=76) . LASSO regression and multivariate Logistic regression analysis were performed to determine the independent risk factors for MVI in HCC, and R software was used to establish a nomogram model for predicting the risk of MVI in HCC before operation. The internal validation of the model was performed by Bootstrap method, external validation of the model was performed by using the validation group. The consistency index, calibration curve and decision curve analysis (DCA) were used to evaluate the discrimination, calibration ability and clinical application value of the nomogram.

Multivariate Logistic regression analysis showed that WBC>7.1×10⁹/L〔OR=3.144, 95%CI (1.301, 7.598) , P=0.011〕, tumor diameter>7.05 cm〔OR=3.836, 95%CI (1.758, 8.372) , P=0.001〕, S-Index>0.097〔OR=3.165, 95%CI (1.024, 9.779) , P=0.040〕, AAR>0.879〔OR=2.146, 95%CI (1.062, 4.337) , P=0.030〕, ANRI>24.074〔OR=2.769, 95%CI (1.175, 6.526) , P=0.020〕 were independent predictors of MVI in HCC. The consistency index of the nomogram model established using the five variables combined with AFP was 0.800〔95%CI (0.739, 0.861) 〕 and 0.755〔95%CI (0.641, 0.868) 〕 in the model group and validation group, respectively. The model fitted well with the calibration prediction curve. The optimal critical value of the nomogram calculated by Youden index was 174 points. The sensitivity, specificity, positive predictive value and negative predictive value at the critical value were 90%, 61%, 71%, and 85% in the model group, and 78%, 71%, 76% and 74% in the validation set, respectively.

The nomogram constructed with AFP>45 ng/mL, WBC>7.1×10⁹/L, tumor diameter>7.05 cm, S-Index>0.097, AAR>0.879, ANRI>24.074 can better predict the risk of preoperative MVI in HCC, the use of this nomogram can conveniently guide the clinical treatment of HCC patients by routine examination test indicators.