Table 2.
Diagnostic power of CTC, US and MMG in breast cancer diagnosis*.
| CTC | 95% CI | US | 95% CI | MMG | 95% CI | |
|---|---|---|---|---|---|---|
| Sensitivity | 0.73 | 0.67 - 0.79 | 0.79 | 0.74 - 0.84 | 0.58 | 0.51 - 0.64 |
| Specificity | 0.92 | 0.88 - 0.95 | 0.81 | 0.75 - 0.86 | 0.92 | 0.88 - 0.95 |
| Accuracy | 0.83 | 0.79 - 0.86 | 0.80 | 0.76 - 0.84 | 0.75 | 0.71 - 0.79 |
| Positive Likelihood Ratio (LR+) | 9.12 | 5.88 - 14.13 | 4.18 | 3.19 - 5.48 | 7.18 | 4.60 - 11.20 |
| Negative Likelihood Ratio (LR-) | 0.29 | 0.24 -0.36 | 0.25 | 0.20 - 0.33 | 0.46 | 0.40 - 0.54 |
| Youden Index | 0.65 | N/A | 0.65 | N/A | 0.50 | N/A |
| Area Under Curve (AUC)# | 0.855 | 0.819 - 0.890 | 0.861 | 0.828 - 0.894 | 0.759 | 0.712 - 0.805 |
| CTC + US | 95% CI | CTC + MMG | 95% CI | US + MMG | 95% CI | |
| Sensitivity | 0.90 | 0.86 - 0.94 | 0.87 | 0.82 - 0.91 | 0.87 | 0.82 - 0.91 |
| Specificity | 0.76 | 0.70 - 0.81 | 0.85 | 0.80 - 0.89 | 0.79 | 0.73 - 0.84 |
| Accuracy | 0.83 | 0.79 - 0.86 | 0.86 | 0.83 - 0.89 | 0.83 | 0.79 - 0.86 |
| Positive Likelihood Ratio (LR+) | 3.69 | 2.94 - 4.63 | 5.89 | 4.32 - 8.03 | 4.12 | 3.21 - 5.30 |
| Negative Likelihood Ratio (LR-) | 0.13 | 0.09 - 0.19 | 0.15 | 0.11 - 0.21 | 0.17 | 0.12 - 0.23 |
| Youden Index | 0.66 | N/A | 0.72 | N/A | 0.66 | N/A |
| Area Under Curve (AUC)# | 0.922 | 0.898 - 0.946 | 0.899 | 0.870 - 0.928 | 0.884 | 0.855 - 0.914 |
CTC, circulating tumor cell; CI, confidence interval; US, ultrasound; MMG, mammogram; N/A,. not applicable.
Confidence intervals for sensitivity, specificity and accuracy are “exact” Clopper-Pearson confidence intervals. Confidence intervals for the likelihood ratios are calculated using the “Log method”.
*CTC, US and MMG cut-off values were determined by the highest Youden index (sensitivity + specificity - 1). When CTC cut-off value was set to 2, and both US BI-RADS and MMG BI-RADS cut-off scores were set to 4b, the highest Youden index of 0.65, 0.65 and 0.5 would be generated for CTC, US, and MMG, respectively. Subjects with more than 2 CTC, or with US or MMG BI-RADS score higher than 4b are classified as CTC, US and MMG positive for diagnosis, respectively. As long as any measurement of composing parameter was higher than its cut-off value, the combination result would be considered as positive for diagnosis.
#AUC was determined by the ROC.