Colorectal cancer screening: Comparison of transferrin and immuno fecal occult blood test

Table 1 Patient demographics

Characteristic	No. of participants	Colorectal cancer	Precancerous lesions	Polyp	Abnormality	Low risk
Total	611	25	60	79	286	447
Sex
Male	310	10	35	49	152	216
Female	301	15	25	30	134	231
Age, yr
Median	50	62	56	53	53	48
Range	14-85	39-85	24-84	25-84	17-85	14-81

Table 2 Positive rate of three fecal occult blood tests in fecal samples from colorectal cancer patients, precancerous lesions subjects, polyp subjects, abnormality subjects and low risk subjects n (%)

Disease (N)	g-FOBT		Tf		IFOBT		Tf+ IFOBT		g-FOBT+ Tf+ IFOBT
	+1	-1	+1	-1	+1	-1	+1	-1	+1	-1
CRC (25)	25 (100)	0 (0)	23 (92)	2 (8)	24 (96)	1 (4)	25 (100)	0 (0)	25 (100)	0 (0)
Precancerous lesions (60)	36 (60)	24 (40)	30 (50)	30 (50)	35 (58)	25 (42)	40 (67)	20 (33)	50 (83)	10 (17)
Polyp (79)	35 (44)	44 (56)	29 (37)	50 (63)	20 (25)	59 (75)	34 (43)	45 (57)	49 (62)	30 (38)
Abnormality (286)	153 (53)	133 (47)	126 (44)	160 (56)	128 (45)	158 (55)	162 (57)	124 (43)	203 (71)	83 (29)
Low risk (447)	148 (33)	299 (67)	105 (23)	342 (77)	109 (24)	338 (76)	154 (34)	293 (66)	221 (49)	226 (51)

¹n (n/N × 100%). Tf: Transferrin; IFOBT: Immuno fecal occult blood test; g-FOBT: Guaiac-fecal occult blood test; CRC: Colorectal cancer.

Table 3 Sensitivity, specificity, positive likelihood ratio and odd ratio of three fecal occult blood tests for detection of colorectal cancer, precancerous lesions and colorectal cancer + precancerous lesions

Test	No. of neoplasms detected	Sensitivity%		Specificity%		Likely ratio(+) (95% CI)	Odd ratio (95% CI)
		n/total	% (95% CI)	n/total	% (95% CI)
CRC
g-FOBT	25	25/25	100 (86.7-100)	367/586	62.6 (58.6-66.5)	2.7 (2.4-3.0)	-
Tf	25	23/25	92 (75.0-97.8)	422/586	72 (68.2-75.5)	3.3 (2.8-3.9)	29.6 (6.8-126.9)
IFOBT	25	24/25	96 (80.5-99.3)	422/586	72 (68.2-75.5)	3.4 (2.9-4.0)	61.8 (8.3-460.2)
Tf+ IFOBT	25	25/25	100 (86.7-100)	358/586	61.1 (57.1-65.0)	2.6 (2.3-2.8)	-
g-FOBT+ Tf+ IFOBT	25	25/25	100 (86.7-100)	266/586	45.4 (41.4-49.4)	1.8 (1.7-2.0)	-
Precancerous lesions
g-FOBT	60	36/60	60 (47.4-71.4)	343/551	62.3 (58.1-66.2)	1.6 (1.3-2.0)	2.5 (1.4-4.3)
Tf	60	30/60	50 (37.7-62.3)	394/551	71.5 (67.6-75.1)	1.8 (1.3-2.3)	2.5 (1.5-4.3)
IFOBT	60	35/60	58.3 (45.7-70.0)	398/551	72.2 (68.4-75.8)	2.1 (1.6-2.7)	3.6 (2.1-6.3)
Tf+ IFOBT	60	40/60	66.7 (54.1-65.3)	338/551	61.3 (57.2-65.3)	1.7 (1.4-2.1)	3.2 (1.8-5.6)
g-FOBT+ Tf+ IFOBT	60	50/60	83.3 (72.0-90.7)	256/551	46.5 (42.3-50.6)	1.6 (1.4-1.8)	4.3 (2.2-8.7)
CRC+ precancerous lesions
g-FOBT	85	61/85	71.8 (61.4-80.2)	343/526	65.2 (61.0-69.2)	2.1 (1.7-2.5)	4.8 (2.9-7.9)
Tf	85	53/85	62.4 (51.7-72.0)	392/526	74.5 (70.6-78.1)	2.5 (2.0 -3.1)	4.8 (3.0-7.8)
IFOBT	85	59/85	69.4 (59.0-78.2)	397/526	75.5 (71.6-79.0)	2.8 (2.3-3.5)	7.0 (4.2-11.5)
Tf+ IFOBT	85	65/85	76.5 (66.4-84.2)	338/526	64.3 (60.1-68.2)	2.1 (1.8-2.5)	5.8 (3.4-9.9)
g-FOBT+ Tf+ IFOBT	85	75/85	88.2 (79.7-93.5)	256/526	48.7 (44.4-53.0)	1.7 (1.5-1.9)	7.1 (3.6-14.1)

Tf: Transferrin; IFOBT: Immuno fecal occult blood test; g-FOBT: Guaiac-fecal occult blood test; CRC: Colorectal cancer; CI: Confidence interval.