Table 3. Area under the receiver operating characteristic (ROC) curve and corresponding cut-off values for cfDNA concentration and cfDNA 100–250 bp fragment fraction for assessing tumor stage in advanced or metastatic NSCLC TKI-naïve patients.

Parameter	AUC	AUC 95% CI	P value	Cut-off	Sensitivity (%)	Specificity (%)
cfDNA concentration (ng/mL)	0.86	0.79–0.93	<0.0001	20.3	72.3	95
100–250 bp cfDNA fraction (%)	0.71	0.59–0.83	0.013	50.5	36.8	95

The table shows the cut-off value and the corresponding sensitivity of each parameter maintaining a specificity of 95% for the test. cfDNA, circulating-free DNA; bp, base pairs, AUC, area under the receiver operating characteristic curve; CI, confidence interval.