Table 2.
Subgroup analysis of diagnostic performance of ctDNA assay for CRC.
| Analysis | Group | Subgroup | SEN (95% CI) | SPE (95% CI) | DOR (95% CI) | AUC |
|---|---|---|---|---|---|---|
| Quantitative analysis | Control type | HC | 0.723 (0.626–0.803) | 0.927 (0.833–0.967) | 24.751 (9.704–63.129) | 0.861 |
| NCD | 0.647 (0.508–0.765) | 0.878 (0.563–0.976) | 13.444 (1.37–131.721) | 0.641 | ||
| Sample size | ≥100 | 0.771 (0.681–0.842) | 0.924 (0.815–0.971) | 32.219 (10.540–98.491) | 0.878 | |
| <100 | 0.545 (0.417–0.667) | 0.904 (0.604–0.983) | 6.753 (2.534–17.998) | 0.694 | ||
| Sample source | Plasma | 0.747 (0.584–0.861) | 0.908 (0.735–0.972) | 22.297 (4.819–103.165) | 0.868 | |
| Serum | 0.701 (0.587–0.795) | 0.929 (0.793–0.978) | 25.591 (7.815–83.805) | 0.841 | ||
| Assay method | RT-PCR | 0.782 (0.680–0.853) | 0.907 (0.767–0.967) | 28.510 (7.995–101.662) | 0.874 | |
| Other | 0.542 (0.445–0.635) | 0.942 (0.786–0.986) | 16.431 (4.418–61.105) | 0.663 | ||
| Qualitative analysis | Region | Asia | 0.623 (0.574–0.669) | 0.906 (0.886–0.922) | 15.968 (11.843–21.529) | 0.862 |
| Other | 0.594 (0.519–0.665) | 0.869 (0.823–0.904) | 9.672 (6.808–13.741) | 0.804 | ||
| Control type | HC | 0.601 (0.554–0.647) | 0.915 (0.895–0.932) | 15.1337 (11.413–20.067) | 0.844 | |
| NCD | 0.672 (0.617–0.723) | 0.809 (0.737–0.865) | 9.188 (6.525–12.934) | 0.774 | ||
| Sample size | >=100 | 0.598 (0.552–0.643) | 0.903 (0.884–0.919) | 13.760 (10.676–17.734) | 0.849 | |
| <100 | 0.662 (0.544–0.762) | 0.819 (0.694–0.900) | 7.445 (4.461–12.425) | 0.759 | ||
| Sample source | Plasma | 0.620 (0.570–0.667) | 0.884 (0.859–0.905) | 12.547 (9.745–16.155) | 0.831 | |
| Serum | 0.563 (0.477–0.645) | 0.920 (0.873–0.951) | 13.108 (7.187–23.906) | 0.817 | ||
| Assay method | MSP | 0.594 (0.551–0.636) | 0.901 (0.882–0.917) | 13.031 (10.216–16.623) | 0.838 | |
| Other | 0.781 (0.611–0.890) | 0.685 (0.482–0.836) | 8.531 (3.834–18.981) | 0.800 | ||
| Methylation gene location | SEPT-9 | 0.679 (0.622–0.732) | 0.904 (0.881–0.923) | 20.551 (14.684–28.760) | 0.883 | |
| Other | 0.577 (0.522–0.631) | 0.885 (0.854–0.910) | 10.297 (7.750–13.681) | 0.802 | ||
| SEPT9 methylation Assay | Region | Asia | 0.679 (0.616–0.737) | 0.922 (0.902–0.938) | 26.096 (17.252–39.471) | 0.904 |
| Other | 0.684 (0.572–0.777) | 0.874 (0.824–0.917) | 14.379 (8.808–23.472) | 0.867 | ||
| Control type | HC | 0.676 (0.609–0.737) | 0.927 (0.900–0.947) | 25.800 (15.869–41.945) | 0.887 | |
| NCD | 0.723 (0.650–0.783) | 0.859 (0.803–0.900) | 17.164 (11.237–26.218) | 0.854 | ||
| Sample size | ≥100 | 0.688 (0.629–0.741) | 0.908 (0.884–0.927) | 21.949 (15.393–31.298) | 0.888 | |
| <100 | 0.603 (0.403–0.773) | 0.832 (0.743–0.894) | 10.289 (3.742–28.293) | 0.847 | ||
| Sample source | Plasma | 0.693 (0.631–0.748) | 0.906 (0.883–0.925) | 22.488 (16.257–31.105) | 0.893 | |
| Serum | 0.575 (0.467–0.676) | 0.880(0.750–0.947) | 9.253 (2.297–37.269) | 0.735 |
Abbreviations: 95% CI, 95% confidence interval; AUC, the area under the curve; CRC, colorectal cancer; ctDNA, circulating tumor DNA; DOR, diagnostic odds ratio; HC, healthy control; MSP, methylation-specific polymerase chain reaction; NCD, non-CRC disease; RT-PCR, real-time quantitative polymerase chain reaction; SEN, sensitivity; SPE, specificity.