Lifestyle factors and long-term survival of gastric cancer patients: A large bidirectional cohort study from China

Table 1 Comparison of 18441 gastric cancer patients' characteristics

Characteristics, n (%)	No. of Patients	BMI at diagnosis				P value	Drinkers			P value	Smokers			P value
		< 18.5	18.5-22.9	23-27.4	≥ 27.5		Never	Yes			Never	Yes
								Ex-drinkers	Current-drinkers			Ex-smokers	Current-smokers
No. of patients	18441 (100)	1193 (6.5)	6872 (37.3)	7310 (39.6)	2196 (11.9)	-	11578 (62.8)	922 (5.0)	5202 (28.2)	-	10244 (55.6)	2315 (12.6)	5156 (28.0)	-
Gender
Male	13533 (73.4)	758 (63.5)	4893 (71.2)	5682 (77.7)	1667 (75.9)		6992 (62.0)	874 (95.8)	4948 (96.6)		5903 (57.6)	2220 (95.5)	4974 (96.5)
Female	4819 (26.1)	435 (36.5)	1979 (28.8)	1628 (22.3)	529 (24.1)	< 0.001	4286 (28.0)	38 (4.2)	174 (3.4)	< 0.001	4341 (42.4)	95 (4.1)	182 (3.5)	< 0.001
Age at diagnosis (yr)
mean (SD)	58.5	56.7	58.2	59.0	58.5	< 0.001	58.6	60.1	58.2	< 0.001	58.0	62.1	58.1	< 0.001
Younger (≤ 35)	653 (3.5)	127 (10.7)	289 (4.2)	152 (2.1)	61 (2.8)		530 (4.6)	13 (1.4)	91 (1.8)		520 (5.1)	22 (1.0)	93 (1.8)
Middle-aged (36-65)	12119 (65.7)	682 (57.2)	4604 (67.0)	5063 (69.3)	1524 (69.4)		7373 (63.7)	657 (71.3)	3887 (74.7)		6640 (64.8)	1415 (61.1)	3872 (75.1)
Older (≥ 66)	5235 (28.4)	383 (32.1)	1976 (28.8)	2090 (28.6)	609 (27.7)	< 0.001	3667 (31.7)	252 (27.3)	1220 (23.5)	< 0.001	3077 (30.0)	877 (37.9)	1188 (23.0)	< 0.001
Weight loss as % of usual weight
None	2858 (15.5)	164 (13.8)	821 (12.0)	813 (11.1)	276 (12.6)		1629 (14.1)	53 (5.8)	642 (12.3)		1437 (14.0)	261 (11.3)	625 (12.1)
0-10	13814 (74.9)	766 (64.2)	5217 (75.9)	5964 (81.6)	1798 (81.9)		8830 (76.3)	766 (83.1)	4030 (77.5)		7825 (76.4)	1835 (79.3)	3980 (77.2)
≥ 10	1769 (9.6)	263 (22.1)	834 (12.1)	533 (7.3)	122 (5.6)	< 0.001	1119 (9.7)	103 (11.2)	530 (10.2)	< 0.001	982 (9.6)	219 (9.5)	551 (10.7)	0.0001
Smoking status
Never smokers	10244 (55.6)	737 (61.8)	3895 (56.7)	4084 (55.9)	1252 (57.0)		9.081 (78.4)	124 (13.5)	1037 (19.9)		-	-	-
Smokers	7471 (40.5)	435 (36.5)	2875 (41.8)	3128 (42.8)	922 (42.0)	0.002	2488 (21.5)	795 (86.2)	4159 (80.0)	< 0.001	-	-	-	-
Current smokers	5156 (28.0)	339 (28.4)	2076 (30.2)	2059 (28.2)	604 (27.5)		1733 (15.0)	250 (27.1)	3158 (60.7)		-	-	-
Ex-smokers	2315 (12.6)	96 (8.1)	799 (11.6)	1069 (14.6)	318 (14.5)	< 0.001	755 (6.5)	545 (59.1)	1001 (19.2)	< 0.001	-	-	-	-
Time since quitting smoking
Short-term (1-9 yr)	1505 (8.2)	75 (6.3)	535 (7.8)	678 (9.3)	197 (9.0)		474 (4.1)	422 (45.8)	597 (11.5)		0 (0.0)	1505 (65.0)	0 (0.0)
Long-term (≥ 10 yr)	810 (4.4)	21 (1.8)	264 (3.8)	391 (5.4)	121 (5.5)	< 0.001	281 (2.4)	123 (13.3)	404 (7.8)	< 0.001	0 (0.0)	810 (35.0)	0 (0.0)	< 0.001
No. of cigarettes (per day)
≤ 20 (1 pack)	5568 (30.2)	338 (28.3)	2190 (31.9)	2318 (31.7)	642 (29.2)		1919 (16.6)	602 (65.3)	3030 (58.3)		0 (0.0)	1770 (76.5)	3798 (73.7)
21-39	457 (2.5)	22 (1.8)	164 (2.4)	198 (2.7)	62 (2.8)		144 (1.2)	36 (3.9)	276 (5.3)		0 (0.0)	115 (5.0)	342 (6.6)
≥ 40 (≥ 2 packs)	708 (3.8)	32 (2.7)	250 (3.6)	302 (4.1)	113 (5.2)	< 0.001	228 (2.0)	76 (8.2)	400 (7.7)	< 0.001	0 (0.0)	208 (9.0)	500 (9.7)	< 0.001
Duration of smoking (yr)
1-29	2805 (15.2)	131 (11.0)	999 (14.5)	1258 (17.2)	383 (17.4)		927 (8.0)	372 (40.4)	1497 (28.8)		0 (0.0)	1230 (53.1)	1575 (30.6)
≥ 30	4037 (21.9)	267 (22.4)	1652 (24.0)	1604 (21.9)	449 (20.5)	< 0.001	1411 (12.2)	359 (38.9)	2252 (43.3)	< 0.001	0 (0.0)	940 (40.6)	3097 (60.1)	< 0.001
Alcohol consumption
Never drinkers	11578 (62.8)	862 (72.3)	4520 (65.8)	4549 (62.2)	1347 (61.3)		-	-	-		9081 (88.7)	755 (32.6)	1733 (33.6)
Drinkers	6124 (33.2)	311 (26.1)	2247 (32.7)	2655 (36.3)	821 (37.4)	< 0.001	-	-	-	-	1161 (11.3)	1546 (66.8)	3408 (66.1)	< 0.001
Current drinkers	5202 (28.2)	272 (22.8)	1909 (27.8)	2249 (30.8)	692 (31.5)		-	-	-		1037 (10.1)	1001 (43.2)	3158 (61.3)
Ex-drinkers	922 (5.0)	39 (3.3)	338 (4.9)	406 (5.6)	129 (5.9)	< 0.001	-	-	-	-	124 (1.2)	545 (23.5)	250 (4.9)	< 0.001
Amount of alcohol consumption
Light drinkers (< 15.6 g/d)	102 (0.6)	3 (0.3)	40 (0.6)	48 (0.7)	11 (0.5)		0 (0.0)	15 (1.6)	87 (1.7)		15 (0.2)	42 (1.8)	45 (0.9)
Moderate drinkers (≥ 15.6 g/d to < 53.5 g/d)	660 (3.6)	30 (2.5)	246 (3.6)	311 (4.3)	62 (2.8)		0 (0.0)	77 (8.4)	583 (11.2)		127 (1.2)	201 (8.7)	329 (6.4)
Heavy drinkers (≥ 53.5 g/d)	3480 (18.9)	167 (14.0)	1277 (18.6)	1488 (20.4)	501 (22.8)	< 0.001	0 (0.0)	593 (64.3)	2887 (55.5)	< 0.001	620 (6.1)	894 (38.6)	1962 (38.1)	< 0.001
H. pylori
No	1506 (8.2)	67 (5.6)	561 (8.2)	668 (9.1)	193 (8.8)		837 (7.2)	152 (16.5)	489 (9.4)		734 (7.2)	272 (11.8)	474 (9.2)
Yes	1167 (6.3)	56 (4.7)	457 (6.7)	503 (6.9)	134 (6.1)	< 0.001	692 (6.0)	74 (8.0)	386 (7.4)	< 0.001	590 (5.8)	169 (7.3)	393 (7.6)	< 0.001
Histologic type
Well	351 (1.9)	27 (2.3)	107 (1.6)	165 (2.3)	48 (2.2)		214 (1.9)	24 (2.6)	107 (2.1)		185 (1.8)	45 (1.9)	115 (2.2)
Moderately	5514 (29.9)	257 (21.5)	2004 (29.2)	2390 (32.7)	758 (34.5)		2300 (28.5)	288 (31.2)	1829 (36.2)		2789 (27.2)	844 (36.5)	1787 (34.7)
Poorly	5824 (31.6)	374 (31.4)	2236 (32.5)	2398 (32.8)	730 (33.2)		3922 (33.9)	233 (25.3)	1567 (30.1)		3643 (35.6)	612 (26.4)	1475 (28.6)
Undifferentiated, anaplastic	3 (0.0)	0 (0.0)	1 (0.0)	2 (0.0)	0 (0.0)	< 0.001	1 (0.0)	0 (0.0)	2 (0.0)	< 0.001	3 (0.0)	0 (0.0)	0 (0.0)	< 0.001
pathologicT
p0	61 (0.3)	2 (0.2)	22 (0.3)	27 (0.4)	10 (0.5)		41 (0.4)	3 (0.3)	17 (0.3)		35 (0.3)	7 (0.3)	19 (0.4)
p1	2778 (15.1)	131 (11.0)	966 (14.1)	1242 (17.0)	412 (18.8)		1810 (15.6)	206 (22.3)	721 (13.9)		1663 (16.2)	347 (15.0)	729 (14.1)
p2	1524 (8.3)	83 (7.0)	528 (7.7)	647 (8.9)	243 (11.1)		955 (8.3)	75 (8.1)	462 (8.9)		834 (8.1)	192 (8.3)	467 (9.1)
p3	3340 (18.1)	169 (14.2)	1233 (17.9)	1459 (20.0)	443 (20.2)		2051 (17.7)	176 (19.1)	1093 (21.0)		1702 (16.6)	497 (21.5)	1120 (21.7)
p4	6545 (35.5)	465 (39.0)	2605 (37.9)	2640 (36.1)	708 (32.2)	< 0.001	4308 (37.2)	266 (28.9)	1882 (36.2)	< 0.001	3888 (38.0)	812 (35.1)	1765 (34.2)	< 0.001
pathologicN
p0	4964 (26.9)	274 (23.0)	1758 (25.6)	2184 (29.9)	685 (31.2)		3149 (27.2)	304 (33.0)	1436 (27.6)		2785 (27.2)	670 (28.9)	1434 (27.8)
p1	2426 (13.2)	161 (13.5)	905 (13.2)	1008 (13.8)	313 (14.3)		1577 (13.6)	116 (12.6)	709 (13.6)		1357 (13.3)	301 (13.0)	744 (14.4)
p2	2549 (13.8)	170 (14.3)	1018 (14.8)	997 (13.6)	327 (14.9)		1639 (14.2)	116 (12.6)	758 (14.6)		1448 (14.1)	316 (13.7)	753 (14.6)
p3	4045 (21.9)	226 (18.9)	1570 (22.9)	1717 (23.5)	464 (21.1)	< 0.001	2633 (22.7)	175 (19.0)	1193 (22.9)	0.007	2384 (23.3)	545 (23.5)	1079 (20.9)	0.018
pathologicM
p0	14785 (80.2)	899 (75.4)	5563 (81.0)	6176 (84.5)	1889 (86.0)		9438 (81.5)	770 (83.5)	4373 (84.1)		8348 (81.5)	1971 (85.1)	4273 (82.9)
p1	2233 (12.1)	203 (17.0)	943 (13.7)	776 (10.6)	211 (9.6)	< 0.001	1460 (12.6)	110 (11.9)	620 (11.9)	< 0.001	1332 (13.0)	231 (10.0)	628 (12.2)	< 0.001
pTNM
I	3340 (18.1)	157 (13.2)	1155 (16.8)	1490 (20.4)	500 (22.8)		2139 (18.5)	221 (24.0)	16 (0.3)		1928 (18.8)	435 (18.8)	922 (17.9)
II	2334 (12.7)	137 (11.5)	843 (12.3)	1012 (13.8)	320 (14.6)		1443 (12.5)	147 (15.9)	922 (17.7)		1210 (11.8)	317 (13.7)	782 (15.2)
III	7712 (41.8)	481 (40.3)	3005 (43.7)	3180 (43.5)	917 (41.8)		5009 (43.3)	312 (33.8)	724 (13.9)		4456 (43.5)	1012 (43.7)	2165 (42.0)
IV	2233 (12.1)	203 (17.0)	943 (13.7)	776 (10.6)	211 (9.6)	< 0.001	1460 (12.6)	110 (11.9)	2301 (44.2)	< 0.001	1332 (13.0)	231 (10.0)	628 (12.2)	< 0.001
Lauren classification
Intestinal	2838 (15.4)	126 (10.6)	988 (14.4)	1304 (17.8)	388 (17.7)		1549 (13.4)	250 (27.1)	995 (19.1)		1279 (12.5)	554 (23.9)	962 (18.7)
Diffuse	2610 (14.2)	154 (12.9)	1017 (14.8)	1095 (15.0)	318 (14.5)		1660 (14.3)	181 (19.6)	726 (14.0)		1547 (15.1)	342 (14.8)	680 (13.2)
Mixed	1799 (9.8)	68 (5.7)	646 (9.4)	795 (10.9)	271 (12.3)	< 0.001	1010 (8.7)	146 (15.8)	621 (11.9)	< 0.001	897 (8.8)	295 (12.7)	583 (11.3)	< 0.001
Linitis plastica
No	17321 (93.9)	1132 (94.9)	6611 (96.2)	7059 (96.6)	2115 (96.3)		11149 (96.3)	892 (96.8)	5011 (96.3)		9844 (96.1)	2244 (96.9)	4978 (96.6)
Yes	181 (1.0)	23 (1.9)	80 (1.2)	59 (0.8)	16 (0.7)	0.005	125 (1.1)	9 (1.0)	44 (0.9)	0.55	117 (1.1)	18 (0.8)	43 (0.8)	0.17
Location
Proximal GC	6704 (36.4)	386 (32.4)	2409 (35.1)	2856 (39.1)	913 (41.6)		3870 (33.4)	318 (34.5)	2447 (47.0)		3147 (30.7)	1193 (51.5)	2298 (44.6)
Distal GC	9.992 (54.2)	704 (59.0)	3966 (57.7)	3948 (54.0)	1141 (52.0)		6884 (59.5)	517 (56.1)	2417 (46.5)		6354 (62.0)	933 (40.3)	2545 (49.4)
Total GC	894 (4.9)	56 (4.7)	353 (5.1)	355 (4.9)	104 (4.7)	< 0.001	558 (4.8)	55 (6.0)	263 (5.1)	< 0.001	507 (5.0)	127 (5.5)	240 (4.7)	< 0.001
Type of gastrectomy
Gastrectomy	15204 (82.5)	930 (78.0)	5623 (81.8)	6248 (85.5)	1885 (85.8)		9662 (83.5)	773 (83.8)	4278 (82.2)		8533 (83.3)	1961 (84.7)	4230 (82.0)
No surgery	3146 (17.1)	263 (22.1)	1246 (18.1)	1061 (14.5)	311 (14.2)	< 0.001	1916 (16.6)	148 (16.1)	924 (17.8)	0.019	1711 (16.7)	353 (15.3)	926 (18.0)	0.005
Surgical margin
Negative	13370 (72.5)	791 (66.3)	5012 (72.9)	5650 (77.3)	1730 (78.8)		8623 (74.5)	684 (74.2)	3899 (75.0)		7622 (74.4)	1755 (75.8)	3841 (74.5)
Positive	443 (2.4)	36 (3.0)	163 (2.4)	195 (2.7)	41 (1.9)	< 0.001	297 (2.6)	21 (2.3)	120 (2.3)	0.83	263 (2.6)	67 (2.9)	108 (2.1)	0.067
Additional therapy
No neo/adjuvant	1564 (8.5)	82 (6.9)	520 (7.6)	701 (9.6)	241 (11.0)		925 (8.0)	128 (13.9)	484 (9.3)		840 (8.2)	242 (10.5)	456 (8.8)
Neoadjuvant	354 (1.9)	25 (2.1)	158 (2.3)	134 (1.8)	33 (1.5)		192 (1.7)	43 (4.7)	113 (2.2)		171 (1.7)	81 (3.5)	97 (1.9)
Adjuvant	4713 (25.6)	244 (20.5)	1743 (25.4)	2044 (28.0)	621 (28.3)		3057 (26.4)	198 (21.5)	1383 (26.6)		2782 (27.2)	503 (21.7)	1354 (26.3)
Neo + adjuvant	613 (3.3)	37 (3.1)	222 (3.2)	272 (3.7)	77 (3.5)	< 0.001	353 (3.1)	63 (6.8)	190 (3.7)	< 0.001	319 (3.1)	136 (5.9)	154 (3.0)	< 0.001

H. pylori: Helicobacter pylori; GC: Gastric cancer.

Table 2 Multivariate survival analysis

Prognostic factors	Total (n = 18322)1				No surgery (n = 3142)2				Gastrectomy (n = 15180)3				Only curative gastrectomy (n = 13695)4
	HR	95%CI		P value	HR	95%CI		P value	HR	95%CI		P value	HR	95%CI		P value
		Lower	Upper			Lower	Upper			Lower	Upper			Lower	Upper
Gender
Male	1.00				1.00				1.00				1.00
Female	1.05	1.00	1.11	0.06	1.07	0.97	1.19	0.19	1.05	0.99	1.11	0.13	1.04	0.97	1.11	0.25
Age at diagnosis (yr)
Younger (≤ 35)	1.00				1.00				1.00				1.00
Middle-aged (36-65)	1.07	0.95	1.19	0.26	0.94	0.76	1.15	0.54	1.14	0.99	1.30	0.06	1.15	1.00	1.33	0.05
Older (≥ 66)	1.10	0.98	1.23	0.12	0.89	0.72	1.11	0.30	1.20	1.05	1.38	0.01	1.21	1.05	1.40	0.01
BMI (kg/m2) at diagnosis
< 18.5	1.00	0.92	1.09	0.99	1.01	0.87	1.18	0.90	1.00	0.90	1.10	0.93	1.02	0.92	1.14	0.72
18.5-22.9	1.00				1.00				1.00				1.00
23-27.4	0.97	0.93	1.02	0.22	0.92	0.84	1.02	0.11	0.99	0.94	1.05	0.73	0.99	0.94	1.05	0.74
≥ 27.5	0.99	0.92	1.06	0.72	0.95	0.82	1.10	0.48	1.01	0.93	1.10	0.85	1.02	0.93	1.11	0.74
Weight loss as % of usual weight
None	1.00				1.00				1.00				1.00
0-10	1.14	1.07	1.20	< 0.001	1.16	1.04	1.30	0.01	1.13	1.05	1.20	0	1.11	1.04	1.19	0
≥ 10	1.24	1.15	1.34	< 0.001	1.22	1.06	1.40	0.01	1.25	1.14	1.38	< 0.001	1.22	1.10	1.34	0
Smoking status
Never smokers	1.00				1.00				1.00				1.00
Current smokers	1.02	0.94	1.10	0.66	1.05	0.89	1.23	0.57	1.01	0.92	1.11	0.78	1.03	0.93	1.14	0.58
Ex-smokers	0.93	0.84	1.03	0.17	0.95	0.76	1.19	0.66	0.93	0.82	1.04	0.20	0.91	0.81	1.03	0.15
Time since quitting smoking
Short-term (1–9 yr)	1.00				1.00				1.00				1.00
Long-term (≥ 10 yr)	1.04	0.91	1.19	0.55	1.02	0.78	1.34	0.87	1.05	0.90	1.22	0.51	1.07	0.91	1.25	0.42
No. of cigarettes (per day)
≤ 20 (1 pack)	1.00				1.00				1.00				1.00
21-39	1.07	0.93	1.22	0.36	1.29	1.00	1.66	0.05	0.98	0.84	1.16	0.84	0.99	0.83	1.17	0.87
≥ 40 (≥ 2 packs)	1.03	0.92	1.16	0.59	0.91	0.72	1.15	0.43	1.09	0.95	1.24	0.22	1.08	0.94	1.24	0.30
Duration of smoking (yr)
1-29	1.00				1.00				1.00				1.00
≥ 30	1.08	1.00	1.16	0.05	0.94	0.81	1.09	0.40	1.14	1.04	1.24	0	1.13	1.04	1.24	0.01
Alcohol consumption
Never drinkers	1.00				1.00				1.00				1.00
Current drinkers	0.82	0.58	1.18	0.29	1.54	0.71	3.37	0.28	0.75	0.50	1.12	0.16	0.88	0.59	1.32	0.54
Ex-drinkers	0.86	0.59	1.24	0.42	1.33	0.63	2.80	0.46	0.75	0.49	1.16	0.19	0.86	0.56	1.32	0.48
Amount of alcohol consumption
Light drinkers (< 15.6 g/d)	1.00				1.00				1.00				1.00
Moderate drinkers (≥ 15.6 g/d to < 53.5 g/d)	1.25	0.86	1.81	0.25	0.97	0.45	2.13	0.95	1.27	0.83	1.94	0.28	1.07	0.70	1.64	0.75
Heavy drinkers (≥ 53.5 g/d)	1.25	0.88	1.79	0.21	0.78	0.37	1.66	0.52	1.37	0.91	2.06	0.13	1.15	0.77	1.73	0.50
pTNM
I	1.00				1.00				1.00				1.00
II	1.48	1.33	1.66	< 0.001	3.65	0.45	29.50	0.23	1.48	1.32	1.65	< 0.001	1.38	1.23	1.56	< 0.001
III	2.31	2.12	2.52	< 0.001	4.07	0.56	29.79	0.17	2.29	2.10	2.49	< 0.001	2.19	2.00	2.39	< 0.001
IV	3.19	2.86	3.55	< 0.001	4.41	0.62	31.18	0.14	3.42	3.04	3.86	< 0.001	3.16	2.79	3.58	< 0.001
Type of gastrectomy
Gastrectomy	1.00				-				-				-
No surgery	1.51	1.40	1.63	< 0.001	-	-	-	-	-	-	-	-	-	-	-	-

¹Adjust for gender, age, pTNM stage, adjuvant therapies, gastrectomy.

²Adjust for gender, age, pTNM stage.

³Adjust for gender, age, pTNM stage, adjuvant therapies.

⁴Adjust for gender, age, pTNM stage, adjuvant therapies.