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

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.