Fecal tumor M2 pyruvate kinase is not a specific biomarker for colorectal cancer screening

Table 1 Comparison of published studies using Fecal M2-PK assay (cut-off value 4 U/mL) for CRC screening (adapted from Shastri et al[2])

Authors	Study design	PatientNo.(M/F)	Averageage(yr)	Sensitivity(%)		Specificity(%)
				CRC	Polyp	CRC	Polyp
#Hardt[4]	Single centre, retrospective	78 (58/29)	68.2	69	50	-	-
Hardt[5]	Multicenter, retrospective	204 (NA)	NA	73	-	78	-
Naumann[6]	Multicenter, prospective	232 (129/112)	NA	85	37	65	-
Vogel[7]	Multicenter, prospective	138 (61/77)	58	77	48	72	-
Shastri[2]	Multicenter, prospective	317 (152/165)	56	81	26	71	71
Tonus[1]	Single centre, retrospective	96 (54/42)	66	78	-	93	-

# Colonoscopy was not done to compare the results of M2-PK. CRC: colorectal cancer; M: male; F: female; NA: not available.