Impact of SNP-SNP interactions of DNA repair gene ERCC5 and metabolic gene GSTP1 on gastric cancer/atrophic gastritis risk in a Chinese population

Table 4 Cumulative effect of the interacting factors of ERCC5 SNPs-GSTP1 rs1696 on atrophic gastritis risk

No. of interacting genotypes	Total population			H. pylori-negative subpopulation			H. pylori-positive subpopulation
	Cases/controls	P1 value	OR (95%CI)	Cases/controls	P2 value	OR (95%CI)	Cases/controls	P2 value	OR (95%CI)
ERCC5 rs2094258-GSTP1 rs1695 on AG risk
0	132/162		1 (Ref.)	57/115		1 (Ref.)	75/47		1 (Ref.)
1	369/310	0.008	1.48 (1.11-1.98)	216/79	0.125	1.35 (0.92-1.97)	216/79	0.017	1.72 (1.10-2.69)
2	133/148	0.782	1.05 (0.74-1.49)	47/106	0.655	0.90 (0.56-1.44)	86/42	0.363	1.270.76-2.14)
		Ptrend = 0.528			Ptrend = 0.720			Ptrend = 0.349
ERCC5 rs873601-GSTP1 rs1695on AG risk
0	321/279		1 (Ref.)	138/206		1 (Ref.)	183/73		1 (Ref.)
1	254/286	0.013	0.73 (0.57-0.94)	99/201	0.061	0.73 (0.53-1.02)	155/85	0.090	0.72 (0.49-1.05)
2	59/55	0.670	0.911 (0.60-1.40)	20/45	0.150	0.66 (0.37-1.16)	39/10	0.241	1.57 (0.74-3.31)
		Ptrend = 0.156			Ptrend = 0.043			Ptrend = 0.907

¹Adjusted by sex, age, and H. pylori infection;

²Adjusted by sex and age. Statistically significant associations were highlighted in bold (P < 0.05). CON: Controls; AG: Atrophic gastritis; ERCC5: Excision repair cross complementing group 5; GSTP1: Glutathione S-transferase pi 1.