Table 2.
Performance of sAxl and AFP in the detection of HCC
| AUC (95% CI) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | Youden’s index | |
|---|---|---|---|---|---|---|
| All HCC vs. HC | ||||||
| AFP | 0.868 (0.829–0.900) | 55.3 | 100 | 100 | 69.1 | 0.55 |
| sAxl | 0.834 (0.792–0.870) | 78.1 | 70.8 | 72.8 | 76.4 | 0.49 |
| sAxl+AFP | 0.937 (0.907–0.959) | 84.5 | 92.3 | 91.6 | 85.6 | 0.77 |
| Very early HCC vs. HC | ||||||
| AFP | 0.797 (0.699–0.874) | 38.5 | 100 | 100 | 61.9 | 0.39 |
| sAxl | 0.848 (0.757–0.914) | 76.9 | 69.2 | 71.4 | 75.0 | 0.46 |
| sAxl+AFP | 0.936 (0.864–0.976) | 80.8 | 92.3 | 91.3 | 82.8 | 0.73 |
| All AFP negative HCC vs. HC | ||||||
| sAxl | 0.803 (0.741–0.855) | 73 | 70.8 | 71.4 | 72.4 | 0.44 |
| Very early AFP negative HCC vs. HC | ||||||
| sAxl | 0.863 (0.767–0.929) | 80 | 69.2 | 72.2 | 77.6 | 0.49 |
| All HCC vs. LC | ||||||
| AFP | 0.771 (0.710–0.833) | 55.3 | 93.3 | 89.2 | 67.6 | 0.49 |
| sAxl | 0.815 (0.747–0.884) | 78 | 66.7 | 70.1 | 75.2 | 0.45 |
| sAxl+AFP | 0.891 (0.847–0.936) | 85.1 | 80.0 | 81.0 | 84.3 | 0.65 |
| Very early HCC vs. LC | ||||||
| AFP | 0.662 (0.513–0.810) | 42.3 | 93.3 | 86.3 | 61.8 | 0.36 |
| sAxl | 0.838 (0.738–0.939) | 80.8 | 66.7 | 70.8 | 77.6 | 0.48 |
| sAxl+AFP | 0.901 (0.823–0.979) | 88.5 | 76.7 | 79.2 | 87.0 | 0.65 |
| All AFP negative HCC vs. LC | ||||||
| sAxl | 0.780 (0.698–0.861) | 73 | 66.7 | 68.7 | 71.2 | 0.40 |
| Very early AFP negative HCC vs. LC | ||||||
| sAxl | 0.858 (0.746–0.969) | 86.7 | 66.7 | 72.3 | 83.4 | 0.53 |
AUC, area under the curve; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value; HCC, hepatocellular carcinoma; AFP, α-fetoprotein; HC, healthy controls; LC, liver cirrhosis.
Diagnostic cutoffs for AFP and sAxl were 20 ng/mL and 14.053 ng/mL, respectively.