Association of XPG rs2094258 polymorphism with gastric cancer prognosis

Table 1 Demographic characteristics of the participants

		Case	Control	X2	P-value
		n = 956	n = 1012
Age (yr)
	≤60	569 (59.5)	637 (62.9)	2.289	0.130
	>60	387 (40.5)	375 (37.1)
Gender
	Male	667 (69.8)	724 (71.5)	0.662	0.416
	Female	289 (30.2)	288 (28.5)
H. pylori infection
	Positive	675 (70.6)	542 (53.6)	59.835	<0.001
	Negative	281 (29.4)	470 (46.4)
Drinking
	No	758 (79.3)	497 (49.1)	2.787	0.095
	Yes	198 (20.7)	515 (50.9)
Smoking
	No	560 (58.6)	517 (51.1)	1.382	0.240
	Yes	396 (41.4)	495 (48.9)

H. pylori: Helicobacter pylori.

Table 2 Single nucleotide polymorphism and genotype distribution between gastric cancer cases and controls

SNP	Genotype	Case	Control	HWE	P-value	OR	95%CI	P-value	OR1	95%CI	P-value
		n = 956	n = 1012
Rs2094258	CC	390 (40.8)	437 (43.2)	0.318	0.853	1.00
	CT	441 (46.1)	464 (45.8)			1.07	0.88-1.29	0.545	1.05	0.86-1.31	0.626
	TT	125 (13.1)	111 (11.0)			1.26	0.94-1.69	0.133	1.19	0.90-1.20	0.249
	Dominant	566 (59.2)	575 (56.8)			1.10	0.92-1.32	0.284	1.06	0.87-1.37	0.388
	Recessive	831 (86.9)	901 (89.0)			1.22	0.93-1.60	0.150	1.19	0.91-1.72	0.303
Rs751402	CC	366 (38.3)	371 (36.7)	0.183	0.913	1.00
	CT	467 (48.8)	476 (47.0)			0.95	0.78-1.16	0.618	0.98	0.77-1.33	0.774
	TT	123 (12.9)	165 (16.3)			0.88	0.67-1.15	0.341	0.90	0.61-1.28	0.491
	Dominant	590 (61.7)	632 (62.5)			0.95	0.79-1.14	0.554	0.95	0.78-1.22	0.711
	Recessive	833 (87.1)	847 (83.7)			0.90	0.71-1.15	0.411	0.93	0.69-1.18	0.487
Rs2296147	TT	599 (62.7)	640 (63.2)	0.076	0.963	1.00
	CT	301 (31.5)	332 (32.9)			0.97	0.80-1.17	0.745	0.97	0.80-1.19	0.674
	CC	56 (5.9)	40 (3.9)			1.50	0.98-2.28	0.059	1.40	0.97-2.50	0.061
	Dominant	357 (37.3)	372 (36.8)			1.03	0.85-1.23	0.789	1.01	0.80-1.38	0.865
	Recessive	900 (94.1)	973 (96.1)			1.51	1.00-2.29	0.050	1.36	0.99-2.49	0.053
Rs1047768	TT	505 (52.8)	540 (53.4)	0.367	0.832	1.00
	CT	379 (39.6)	406 (40.1)			1.00	0.83-1.20	0.985	1.00	0.80-1.28	0.989
	CC	72 (7.6)	66 (6.5)			1.17	0.82-1.66	0.395	1.11	0.79-1.92	0.505
	Dominant	451 (47.2)	472 (46.6)			1.02	0.86-1.22	0.812	1.01	0.81-1.45	0.897
	Recessive	884 (92.5)	946 (93.5)			1.17	0.83-1.65	0.381	1.12	0.74-1.84	0.561
Rs873601	GG	271 (28.3)	288 (28.5)	0.247	0.884	1.00
	AG	475 (49.7)	514 (50.8)			0.98	0.80-1.21	0.865	0.99	0.63-1.88	0.931
	AA	210 (22.0)	210 (20.7)			1.06	0.83-1.37	0.638	1.03	0.71-2.01	0.807
	Dominant	685 (71.7)	724 (71.5)			1.12	0.92-1.37	0.245	1.07	0.82-1.94	0.466
	Recessive	746 (78.0)	802 (79.2)			1.08	0.87-1.33	0.511	0.98	0.88-1.37	0.685

¹OR was calculated by Logistic regression method after adjusting for age and gender. H. pylori: Helicobacter pylori infection status; SNP: Single nucleotide polymorphism; HWE: Hardy-Weinberg equilibrium; OR: Odds ratio.

Table 3 Genotypes of single nucleotide polymorphism and 5-year survival status of gastric cancer cases

SNP	Genotype	Case	Death (%)	5-yr survival rate (%)	P-value1
Rs2094258	CC	388	157 (40.5)	59.4	0.032
	CT	440	203 (46.1)	53.7
	TT	123	68 (55.3)	45.4
Rs751402	CC	363	162 (44.6)	55.3	0.523
	CT	465	216 (46.5)	53.3
	TT	121	50 (41.3)	58.9
Rs2296147	TT	589	281 (47.7)	52.0	0.217
	CT	297	124 (41.8)	57.6
	CC	50	23 (46.0)	57.7
Rs1047768	TT	501	243 (48.5)	51.2	0.102
	CT	375	152 (40.5)	59.1
	CC	67	33 (49.3)	53.4
Rs873601	GG	268	131 (48.9)	51.2	0.362
	AG	472	203 (43.0)	56.8
	AA	207	94 (45.4)	54.7

¹P was calculated by log-rank test. SNP: Single nucleotide polymorphism.

Table 4 Univariate analysis of associations between influencing factors and 5-year survival of gastric cancer cases

Variable	Classification	n	Death (%)	5-yr survival rate (%)	P-value1
Gender	Male	667	303 (45.4)	54.2	0.399
	Female	289	125 (43.3)	56.1
Age (yr)	≤60	569	235 (41.3)	58.5	0.011
	>60	387	193 (49.9)	49.7
Drinking	No	758	335 (44.2)	55.6	0.259
	Yes	198	93 (47.0)	52.9
Smoking	No	560	244 (43.6)	55.9	0.417
	Yes	396	184 (46.5)	53.3
H. pylori infection	Negative	281	118 (42.0)	58.1	0.284
	Positive	675	310 (45.9)	51.4
TNM stage	I	178	18 (10.1)	87.7	<0.001
	II	366	129 (35.2)	66.9
	III	404	281 (69.6)	29.8
Differentiation	Poor	661	329 (49.8)	50.0	<0.001
	Moderate or high	280	99 (35.4)	66.7
Lymphovascular invasion	Negative	269	57 (21.2)	79.6	<0.001
	Positive	675	371 (55.0)	44.8
Neural invasion	Negative	396	132 (33.3)	67.4	<0.001
	Positive	548	296 (54.0)	45.7
Chemotherapy	No	361	281 (77.8)	22.9	<0.001
	Yes	592	147 (24.8)	75.1

Missing values: 8 for tumor–node–metastasis stage, 15 for differentiation, 12 for lymphovascular invasion and neural invasion, and 3 for chemotherapy.

¹P was calculated by log-rank test. H. pylori: Helicobacter pylori; TNM: Tumor–node–metastasis.

Table 5 Multivariate analysis of gastric cancer survival

Variable	Comparison	HR1	95%CI	P-value
Differentiation	Poor vs Moderate or high	4.51	1.99-8.23	<0.001
Lymphovascular invasion	Positive vs Negative	1.97	1.44-3.01	<0.001
Chemotherapy	Yes vs No	0.81	0.63-0.98	0.041
Rs2094258	Increase in C allele	1.19	1.02-1.45	0.037

¹HR was calculated by Cox regression model. HR: Hazard ratio.