Table 4.

Comparison of positive ratio and specificity of three markers in peripheral blood detected by real-time and conventional RT-PCR respectively

		CEA	CK19	CK20
Present study	P (%)	35.7	40.5	28.6
	S (%)	96.7	96.7	93.3
Previous real-time RT-PCR detection	P (%)	24.8 (Schuster et al., 2004); 52.9 (Öberg et al., 2004)	20.2 (Hardingham et al., 2000)	22.2 (Giribaldi et al., 2006)
	S (%)	100 (Schuster et al., 2004)	97.8 (Stathopoulou et al., 2003)	100 (Giribaldi et al., 2006)
Conventional RT-PCR detection	P (%)	69 (Fiorella et al., 2001)	64 (Wong et al., 2001); 75 (Gradilone et al., 2003)	30 (Vlems et al., 2002); 44.8 (Zhang et al., 2003)
	S (%)	96.7 (Fiorella et al., 2001); 94 (Piva et al., 2000)	81 (Wong et al., 2001); 71 (Ko et al., 2000)	78.7 (Vlems et al., 2002);76 (Jung et al., 1999)

Note: P: Positive ratio (%); S: Specificity (%)