Table 2. Concordances between the three CTC detection techniques.

	K coefficient	P-value	Degree of agreement	Agreement (%)
Comparison with the CellSearch CTC test
AdnaTest	0.543	<0.001	Moderate	81
RT–PCR for CK-19	0.356	0.002	Fair	72
RT–PCR for mammaglobin	0.220	0.04	Fair	60
RT–PCR for CK-19 and/or mammaglobin	0.203	0.04	Fair	57
Comparison with the AdnaTest
RT–PCR for CK-19	0.415	<0.001	Moderate	78
RT–PCR for mammaglobin	0.082	0.37	Slight	53
RT–PCR for CK-19 and/or mammaglobin	0.109	0.189	Slight	50

Abbreviations: CTC=circulating tumour cell; ER=oestrogen receptor; PR=progesterone receptor; RT–PCR=reverse transcription–PCR.