Table 4.
The diagnostic efficiency of CEA, CA19-9, FIT, composite score (P), and combined analysis in the diagnosis of CRC vs polyp groups
| Independent variable | Sensitivity | Specificity | PPV | NPV | AUC (95% CI) |
| CRC vs polyps | |||||
| CEA | 51.0% | 75.4% | 62.4% | 65.8% | 0.731 (0.664–0.798) |
| CA19-9 | 16.4% | 94.6% | 70.8% | 58.6% | 0.683 (0.614–0.753) |
| FIT | 66.4% | 84.6% | 77.5% | 75.9% | 0.781 (0.718–0.844) |
| Septin9 | 83.7% | 94.6% | 92.6% | 87.9% | 0.901 (0.854–0.947) |
| SDC2 | 76.9% | 90.8% | 87.0% | 83.1% | 0.855 (0.801–0.908) |
| BCAT1 | 83.7% | 93.9% | 91.6% | 87.8% | 0.908 (0.864–0.952) |
| Composite score (P) | 82.7% | 96.9% | 95.6% | 87.5% | 0.914 (0.871–0.957) |
| CEA + CA19-9 | 66.4% | 70.0% | 63.9% | 72.2% | 0.743 (0.679–0.807) |
| Composite score (P) + CEA | 81.7% | 96.2% | 94.4% | 86.8% | 0.944 (0.915–0.972) |
| Composite score (P) + CEA + CA19-9 | 78.9% | 96.2% | 94.3% | 85.0% | 0.930 (0.895–0.965) |
| Composite score (P) + FIT | 83.7% | 96.9% | 95.6% | 88.1% | 0.952 (0.923–0.980) |
| Composite score (P) + CEA + FIT | 84.6% | 95.4% | 93.6% | 88.6% | 0.962 (0.941–0.983) |
| Composite score (P) + CEA + CA19-9 + FIT | 81.7% | 94.6% | 92.4% | 86.6% | 0.953 (0.928–0.978) |
The cutoff value for CEA and CA19-9 was 5 and 30 ng/mL, respectively. The optimal cutoff point for each methylated gene was chosen as the value that maximized the Youden index according to the CRC and control group (polyps and healthy person). The cutoff value for Septin9, SCD2, BCAT1, and composite core (P) is 41.9, 44.5, 45.0, and 2.15, respectively.
AUC, area under the curve; CA19-9, carbohydrate antigen 19-9; CEA, carcinoembryonic antigen; CI, confidence interval; CRC, colorectal cancer; FIT, fecal immunochemical test for hemoglobin; NPV, negative predictive value; PPV, positive predictive value.
*P < 0.05, **P < 0.001.