Analysis of demographic characteristics in 3242 young age gastric cancer patients in Korea

Table 1 Demographic and clinicopathologic features of young age in control group n (%)

Features	Group A (n = 350)	Group B (n = 1500)	Group C (n = 1150)	Whole (n = 3000)	P-value
Age (median, yr)	24 ± 1.3	34 ± 2.4	44 ± 3.7	35 ± 4.9	NS
Sex					< 0.05
Male	150 (42.9)	750 (50.0)	750 (65.2)	1650 (55.0)
Female	200 (52.1)	750 (50.0)	400 (34.8)	1350 (45.0)
Indication of endoscopy					NS
No symptom	117 (33.4)	514 (34.2)	499 (43.4)	1130 (37.7)
Dyspepsia	211 (60.3)	798 (53.2)	687 (59.7)	1696 (56.5)
Weight loss	13 (4.7)	26 (1.7)	28 (2.4)	67 (2.2)
Nausea/poor oral intake	54 (15.4)	155 (10.3)	308 (26.8)	517 (17.2)
Others	17 (4.9)	37 (2.5)	28 (2.4)	82 (2.7)
H. pylori (+) & combined IM					< 0.05
Male	5 (3.3)	65 (4.3)	74 (9.9)	144 (8.7)
Female	11 (5.5)	89 (11.9)	56 (14.0)	156 (11.6)

Group A, 18-30 years of age; Group B, 31-40 years of age; Group C, 41-45 years of age; Whole, 18-45 years of age. NS: Not significant; IM: Intestinal metaplasia; H. pylori: Helicobacter pylori.

Table 2 Demographic and clinicopathologic features of young age GC patients n (%)

Features	Group A (n = 371)	Group B (n = 1584)	Group C (n = 1287)	Whole (n = 3242)	P-value
Age (median, yr)	26 ± 3.2	36 ± 2.8	43 ± 1.4	38 ± 5.6	NS
Sex					< 0.05
Male	144 (38.8)	798 (50.4)	805 (62.5)	1747 (53.9)
Female	227 (61.2)	786 (49.6)	482 (37.5)	1495 (46.1)
Survival (median, mo)1	29.8 ± 4.2	31.7 ± 5.3	33.2 ± 3.8	32.4 ± 3.3	NS
Tumor size (mean, cm)	5.6 ± 3.2	5.2 ± 3.8	4.9 ± 2.9	5.14 ± 4.4	NS
Number					< 0.05
Multiple	1 (0.2)	5 (0.3)	8 (0.6)	14 (0.4)
Single	370 (99.8)	1579 (99.8)	1279 (99.4)	3228 (99.6)
Site of disease					< 0.05
Antrum	71 (19.1)	442 (27.9)	617 (48.0)	1130 (34.9)
Body (lower and middle)	84 (22.6)	365 (23.0)	308 (23.9)	757 (23.3)
Upper body and cardia	140 (37.8)	428 (27.1)	218 (16.9)	786 (24.2)
Diffuse	76 (20.5)	349 (22.0)	144 (11.2)	569 (17.6)
Pathology					< 0.05
Adenocarcinoma
Male	63 (43.8)	401 (50.3)	499 (62.0)	963 (55.1)
Female	87 (38.3)	347 (44.1)	250 (51.9)	684 (45.8)
Signet ring cell carcinoma
Male	81 (56.2)	397 (49.7)	306 (38.0)	784 (44.9)
Female	140 (61.7)	439 (55.9)	232 (48.1)	811 (54.2)
Stage of disease					< 0.05
Localized to stomach	34 (9.2)	190 (12.0)	181 (14.1)	405 (12.5)
Regional metastasis2	71 (19.1)	491 (31.0)	475 (36.9)	1037 (32.0)
Distant metastasis	266 (71.7)	903 (57.0)	631 (49.0)	1800 (55.5)
Coincidence of IM					< 0.05
Male	9 (6.3)	168 (21.1)	249 (31.0)	426 (24.4)
Female	13 (5.7)	121 (15.4)	97 (20.1)	231 (15.5)
H. pylori (+)	25 (6.7)	378 (23.9)	472 (36.7)	875 (27.0)	< 0.05

¹Survival analysis was performed using the Kaplan-Meier method;

²This included node metastasis.

Table 3 Frequency of control group and young age GC, age-adjusted OR estimates and 95% CI by demographic and clinical characteristics, Korea, 1990 to 2008 n (%)

Risk factors	GCs		Controls		Age-adjusted OR		95% CI		P-value
	Male	Female	Male	Female	Male	Female	Male	Female	Male	Female
High-risk diet1
Whole	694 (39.7)	440 (29.4)	341 (20.7)	265 (19.6)	2.53	1.71	2.17-2.95	1.34-2.03	< 0.001	< 0.001
Group A	54 (37.5)	40 (27.8)	31 (20.7)	25 (16.7)	2.30	1.50	1.37-3.87	0.87-2.57	0.002	0.034
Group B	311 (39.0)	239 (30.4)	153 (20.4)	151 (20.1)	2.49	1.73	1.99-3.13	1.37-1.29	< 0.001	< 0.001
Group C	329 (40.9)	161 (33.4)	157 (22.0)	89 (22.3)	2.61	1.75	2.08-3.27	1.307-2.37	< 0.001	< 0.001
Heavy smoking2
Whole	528 (30.2)	241 (16.1)	264 (16.0)	137 (10.1)	2.27	1.70	1.93-2.69	1.36-2.13	< 0.001	< 0.001
Group A	51 (35.4)	34 (15.0)	30 (20.0)	19 (9.5)	2.19	1.68	1.30-3.72	0.92-3.05	0.003	0.031
Group B	244 (30.6)	143 (18.2)	119 (15.9)	83 (11.1)	2.34	1.79	1.82-2.99	1.34-2.39	< 0.001	< 0.001
Group C	233 (28.9)	64 (13.2)	115 (15.3)	35 (8.75)	2.25	1.60	1.75-2.89	1.03-2.47	< 0.001	0.035
Heavy alcohol drinking3
Whole	608 (34.8)	168 (11.2)	301 (18.2)	91 (6.7)	2.39	1.52	2.04-2.81	1.34-2.29	< 0.001	< 0.001
Group A	54 (37.5)	26 (11.5)	28 (18.7)	12 (6.0)	2.61	2.02	1.54-4.45	0.99-4.13	< 0.001	0.052
Group B	293 (36.7)	81 (10.3)	142 (18.9)	47 (6.3)	2.48	1.72	1.97-3.14	1.18-2.50	< 0.001	0.005
Group C	261 (32.4)	61 (12.7)	131 (17.5)	32 (8.0)	2.14	1.73	1.68-2.72	1.60-2.54	< 0.001	0.019
Low socioeconomic condition4
Whole	414 (23.7)	323 (21.6)	279 (16.9)	206 (15.3)	1.53	1.53	1.29-1.81	1.26-1.86	< 0.001	< 0.001
Group A	28 (19.4)	44 (19.3)	21 (14)	27 (13.5)	1.42	1.54	0.76-2.64	0.99-3.03	0.003	0.009
Group B	191 (23.9)	168 (21.4)	135 (18.0)	122 (16.3)	1.43	1.40	1.12-1.84	1.082-1.81	0.004	0.011
Group C	195 (24.2)	111 (23.0)	123 (16.4)	57 (14.2)	1.63	1.80	1.27-2.10	1.27-2.56	< 0.001	0.001
Urban residence
Whole	947 (54.2)	805 (53.8)	711 (43.1)	574 (42.5)	1.56	1.58	1.37-1.79	1.36-1.83	< 0.001	< 0.001
Group A	84 (58.3)	132 (58.1)	67 (44.7)	99 (49.5)	1.48	1.42	0.93-1.23	0.973-2.08	0.002	0.073
Group B	454 (56.9)	434 (55.2)	331 (44.1)	322 (42.9)	1.67	1.64	1.37-2.04	1.34-2.00	< 0.001	< 0.001
Group C	409 (50.8)	239 (49.6)	313 (38.9)	153 (38.2)	1.44	1.60	1.18-1.76	1.21-2.08	0.003	0.001
Occupational environment
Whole	588 (33.6)	331 (22.1)	315 (19.1)	181 (13.4)	2.15	1.84	1.84-2.52	1.51-2.24	< 0.001	< 0.001
Group A	44 (30.6)	47 (20.7)	24 (16.0)	29 (14.5)	2.31	1.54	1.32-4.05	0.93-2.56	0.004	0.094
Group B	263 (33.0)	181 (23.0)	140 (18.7)	98 (13.1)	2.14	1.99	1.69-2.71	1.52-2.61	< 0.001	< 0.001
Group C	281 (34.9)	103 (21.4)	151 (20.1)	54 (13.5)	2.13	1.74	1.69-2.68	1.22-2.50	< 0.001	0.003
Family history of GC5
Whole	150 (8.6)	102 (6.8)	36 (2.2)	28 (2.1)	4.21	3.46	2.91-6.10	2.26-5.29	< 0.001	< 0.001
Group A	11 (7.6)	14 (6.2)	3 (2.0)	4 (2.0)	4.05	3.22	1.10-14.84	1.04-9.95	0.035	0.042
Group B	68 (8.5)	53 (6.7)	17 (2.3)	15 (2.4)	4.01	3.54	2.34-6.90	1.98-6.34	< 0.001	< 0.001
Group C	71 (8.8)	35 (7.2)	16 (2.1)	9 (2.3)	4.17	3.40	2.43-7.15	1.62-7.17	< 0.001	0.001
H. pylori (+) & combined IM
Whole	367 (21.0)	231 (15.5)	144 (8.7)	156 (11.6)	2.78	1.40	2.26-3.42	1.13-1.74	< 0.001	< 0.001
Group A	11 (7.6)	13 (5.7)	5 (3.3)	11 (5.5)	2.40	1.04	0.71-7.08	0.46-2.39	0.051	0.192
Group B	155 (19.4)	121 (15.4)	65 (4.3)	89 (11.9)	2.54	1.35	1.87-3.46	1.00-1.81	< 0.001	0.045
Group C	201 (25.0)	97 (20.1)	74 (9.9)	56 (14.0)	3.04	1.55	2.28-4.06	1.08-2.22	< 0.001	0.017
BMI > 35
Whole	374 (21.4)	270 (18.1)	201 (12.4)	159 (11.8)	1.94	1.65	1.63-2.37	1.34-2.04	< 0.001	< 0.001
Group A	30 (20.8)	35 (15.4)	18 (12.0)	19 (9.5)	1.93	1.74	1.09-2.35	0.96-3.15	0.043	0.066
Group B	176 (22.1)	139 (17.7)	95 (12.7)	89 (11.9)	1.95	1.60	1.49-2.56	1.20-2.12	< 0.001	0.001
Group C	168 (20.9)	96 (19.9)	92 (12.3)	51 (12.8)	1.89	1.70	1.43-2.49	1.78-2.46	< 0.001	0.005

¹High-risk diet is defined as more frequent intake of beef and canned, smoked, and salted food and less frequent intake of fresh fruit/vegetables;

²Heavy smoking is defined as more than 20 pack-years;

³Heavy alcohol intake is defined as more than 60 g/d;

⁴Socioeconomic conditions were evaluated by household income, stratified into 3 groups based on income epidemiology in Korea. This condition comes under the lowest income group;

⁵Family history was defined as first-degree relative with GC. The 3000 normal controls included 1650 males and 1350 females. Group A, 18-30 years of age, n = 350; Group B, 31-40 years of age, n = 1500; Group C, 41-45 years of age, n = 1150; Whole, 18-45 years of age, n = 3000. The 3242 young age GC included 1747 males and 1495 females. Group A, 18-30 years of age, n = 371; group B, 31-40 years of age, n = 1584; group C, 41-45 years of age, n = 1287; whole, 18-45 years of age, n = 3242. GC: Gastric carcinoma; OR: Odds ratio; CI: Confidence interval; BMI: Body mass index.

Table 4 Frequency of control group and young age GC, age-adjusted OR estimates and 95% CI by hormonal and reproductive characteristics, Korea, 1990 to 2008 n (%)

Risk factors	GCs	Controls	OR	95% CI	P-value
Frequent use of oral contraceptives	432 (28.9)	201 (14.0)	2.50	2.06-3.00	< 0.001
Age at first pregnancy (≥ 5 mo)1
Age < 25	225 (15.1)	243 (17.0)	0.86	0.70-1.05	0.127
Age ≥ 25, < 35	848 (56.7)	977 (68.3)	1.05	0.73-1.50	0.438
Age ≥ 35	422 (28.2)	211 (14.7)	2.27	1.89-2.73	< 0.001
Parity (live births)
Nullipara or few (1-2)	779 (52.1)	487 (34.0)	2.11	182-2.45	< 0.001
Many (≥ 3)	431 (28.8)	629 (44.0)	0.52	0.44-0.60	< 0.001
History of lactation	313 (20.9)	414 (28.9)	0.68	0.58-0.79	< 0.001
Poor nutritional status2	252 (16.9)	122 (8.5)	2.12	1.73-2.73	< 0.001
Age at menarche (yr)
Age < 12	308 (20.6)	258 (18.0)	1.18	0.98-1.14	0.078
Age ≥ 12, < 16	956 (63.9)	930 (65.0)	0.95	0.62-1.44	0.102
Age ≥ 16	231 (15.5)	243 (17.0)	0.89	0.73-1.09	0.262
Premenopausal state (preoperative)	134 (9.0)	138 (9.6)	0.92	0.72-1.18	0.526
Other gynecologic malignancy3	19 (1.3)	16 (1.1)	1.14	0.58-2.22	0.237

¹Pregnancy was maintained for at least 5 mo;

²This condition was during pregnancy;

³These conditions included estrogen-associated cancers such as breast, ovarian, and uterine. GC vs control = 1495 vs 1431.