Protective effects of female reproductive factors on gastric signet-ring cell carcinoma

Table 1 Characteristics of 1431 gastric cancer patients with signet ring cells

Characteristics	Overall (n = 1431, %)	Male (n = 935, 65.3%)	Female (n = 496, 34.7%)	P value1
Age (yr)
mean ± SD	56.3 ± 11.3	57.5 ± 10.7	54.2 ± 12.1	< 0.01
< 50	386 (27.0)	213 (55.2)	173 (44.8)	< 0.01
≥ 50, < 60	444 (31.0)	303 (68.2)	141 (31.8)
≥ 60	601 (42.0)	419 (69.7)	182 (30.3)
BMI (kg/m2)
mean ± SD	23.8 ± 3.4	24.3 ± 3.4	22.9 ± 3.3	< 0.01
> 24	659 (46.1)	501 (76.0)	158 (24.0)	< 0.01
≤ 24	772 (54.0)	434 (56.2)	338 (43.8)
Smoke				< 0.01
No	822 (57.4)	346 (42.1)	476 (57.9)
Yes	609 (42.6)	589 (96.7)	20 (3.3)
Drink				< 0.01
No	821 (57.4)	354 (43.1)	467 (56.9)
Yes	610 (42.6)	581 (95.3)	29 (4.8)
Tumor site2				< 0.01
Upper	334 (23.3)	271 (81.1)	63 (18.9)
Middle	345 (24.1)	205 (59.4)	140 (40.6)
Lower	662 (46.3)	416 (62.8)	246 (37.2)
Others	90 (6.3)	43 (47.8)	47 (52.2)
Histology differentiation				0.23
Well-/moderately differentiated	29 (2.1)	22 (75.9)	7 (24.1)
Poorly/undifferentiated	1326 (97.9)	864 (65.2)	462 (34.8)
Signet-ring cell proportion (%)				0.02
≤ 10	155 (10.8)	117 (75.5)	38 (24.5)
> 10, ≤ 50	954 (66.7)	616 (74.6)	338 (35.4)
> 50, ≤ 90	235 (16.4)	143 (60.9)	92 (39.2)
> 90	87 (6.1)	59 (67.8)	28 (32.2)
Lauren type				< 0.01
Intestinal	73 (5.1)	61 (83.6)	12 (16.4)
Diffused	910 (63.6)	557 (61.2)	353 (38.8)
Mixed	353 (24.7)	261 (73.9)	92 (26.1)
Unknown	95 (6.6)	56 (59.0)	39 (41.0)
T stage				0.02
T1	411 (28.7)	246 (59.9)	165 (40.2)
T2	172 (12.0)	119 (69.2)	53 (30.8)
T3	322 (22.5)	227 (70.5)	95 (29.5)
T4	526 (36.8)	343 (65.3)	183 (34.8)
N stage				0.54
N0	573 (40.0)	365 (63.7)	208 (36.3)
N1	192 (13.4)	130 (67.7)	62 (32.3)
N2	219 (15.3)	150 (68.5)	69 (31.5)
N3	447 (31.2)	290 (64.9)	157 (35.1)
Metastasis				< 0.01
No	1348 (94.2)	892 (66.2)	456 (33.8)
Yes	83 (5.8)	43 (51.8)	40 (48.2)
Adjuvant chemotherapy				0.51
No	924 (64.6)	598 (64.7)	326 (35.3)
Yes	507 (35.4)	337 (66.5)	170 (33.5)
Neoadjuvant chemotherapy				0.72
No	1315 (91.9)	861 (65.5)	454 (34.5)
Yes	116 (8.1)	74 (63.8)	42 (36.2)
Nerve invasion				0.02
No	313 (21.9)	184 (58.8)	129 (41.2)
Yes	714 (49.9)	477 (66.8)	237 (33.2)
Unknown	404 (28.2)	274 (67.8)	130 (32.2)
Lymphovascular invasion				0.02
No	416 (29.1)	249 (59.9)	167 (40.1)
Yes	554 (38.7)	373 (67.3)	181 (32.7)
Unknown	461 (32.2)	313 (67.9)	148 (32.1)
HER-2				0.28
Negative	1082 (85.3)	702 (64.9)	380 (35.1)
Positive	187 (14.7)	129 (69.0)	58 (31.0)
Lymph nodes removed				< 0.01
≤ 16	171 (12.0)	131 (76.6)	40 (23.4)
> 16, ≤ 30	585 (40.9)	395 (67.5)	190 (32.5)
> 30	675 (47.2)	409 (60.6)	266 (39.7)

¹The P values for age and BMI (continuous variables) were calculated from Wilcoxon–Mann–Whitney test; The P value for other categorical variables were calculated from χ² test.

²Tumor site was divided by upper (cardia, fundus, gastroesophageal junction), middle (body, lesser/greater curvature), lower (antrum, pylorus) and other (gastric remnant, anastomosis, linitis plastica) parts of the stomach.

P < 0.05 indicates statistical significance. Row percentage was reported for the overall sample. BMI: Body mass index; HER-2: Human epidermal growth factor receptor 2.