Cancer/testis antigen, Kita-Kyushu lung cancer antigen-1 and ABCD stratification for diagnosing gastric cancers

Table 3 Expression of Kita–Kyushu lung cancer antigen-1 and parameters

		Total (n = 77)	KK-LC-1 positive (n = 63)	KK-LC-1 negative (n = 14)	KK-LC-1 expression rate (%)	P value
Anti-H. pylori IgG titer	< 20 U/mL: negative	17	9	8	52.9	0.0087
	≥ 20 U/mL: positive	60	54	6	90
PG I	≤ 70 ng/mL	76	62	14	81.5	0.9226 (NS)
	> 70 ng/mL	1	1	0	100
PG I/PG II ratio	≤ 3	64	55	9	85.9	0.0526 (NS)
	> 3	13	8	5	61.5
PG method	PG I ≤ 70 and PG I/II ≤ 3	63	54	9	85.7	0.1173 (NS)
	Other	14	9	5	64.3
ABCD stratification (H. pylori infection/PG method)	A (negative/negative)	3	1	2	33	0.0005 (C vs others, Fisher’s exact test)
	B (positive/negative)	11	8	3	72.7
	C (positive/positive)	49	46	3	93.9
	D (negative/positive)	14	8	6	57.1

KK-LC-1: Kita–Kyushu lung cancer antigen-1; H. pylori: Helicobacter pylori; NS: Not significant.