Table 3. Results for measurement of serum DKK1, CEA or both in detection of bone metastases.

Variables	AUC (95% CI)	Cutoff value	Sensitivity (%)	Specificity (%)
CEA	0.577	3.03 (ng/ml)	81.3	67.1
	(0.511–0.644)
DKK1	0.791	311.8 (pg/ml)	77.1	71.4
	(0.739–0.843)
CEA + DKK1	0.797		82.9	68.9
	(0.746–0.848)

Abbreviations: DKK1, Dickkopf-1; CEA, carcinoembryonic antigen; ROC, receiver operating characteristic; AUC, area under curve.