Table 1.

Baseline characteristics of patients

Characteristic	Cohort			P
	Overall	Kraków	Lublin
	(N = 1,743)	(N = 1,479)	(N = 264)
Gender, male	1,177 (68%)	1,018 (69%)	159 (60%)	0.006
Age, years	65 (55, 72)	65 (56, 73)	61 (53, 69)	< 0.001
Tumour location				< 0.001
lower	606 (35%)	540 (37%)	66 (25%)
middle	604 (35%)	485 (33%)	119 (45%)
upper	420 (24%)	341 (23%)	79 (30%)
diffuse infiltrative	113 (6.5%)	113 (7.6%)	0 (0%)
Tumour size, mm	50 (30, 80)	52 (30, 80)	31 (20, 50)	< 0.001
Lauren type				< 0.001
intestinal	871 (50%)	742 (50%)	129 (49%)
diffuse	632 (36%)	556 (38%)	76 (29%)
mixed	240 (14%)	181 (12%)	59 (22%)
Tumour grade				< 0.001
1	207 (12%)	196 (13%)	11 (4.2%)
2	513 (30%)	400 (27%)	113 (43%)
3	1,016 (59%)	877 (60%)	139 (53%)
Type of gastrectomy				< 0.001
distal	484 (28%)	403 (27%)	81 (31%)
proximal	181 (10%)	132 (8.9%)	49 (19%)
total	1,078 (62%)	944 (64%)	134 (51%)
Lymph nodes examined	26 (17, 37)	24 (15, 32)	28 (18, 38)	< 0.001
Multivisceral resection	507 (29%)	443 (30%)	64 (24%)	0.06
Neoadjuvant treatment	363 (21%)	156 (11%)	207 (78%)	< 0.001
pT classification				0.003
T1a	140 (8.0%)	112 (7.6%)	28 (11%)
T1b	149 (8.5%)	132 (8.9%)	17 (6.4%)
T2	194 (11%)	150 (10%)	44 (17%)
T3	763 (44%)	651 (44%)	112 (42%)
T4a	287 (16%)	244 (16%)	43 (16%)
T4b	210 (12%)	190 (13%)	20 (7.6%)
pN classification				< 0.001
N0	635 (36%)	513 (35%)	122 (46%)
N1	226 (13%)	191 (13%)	35 (13%)
N2	241 (14%)	199 (13%)	42 (16%)
N3a	331 (19%)	297 (20%)	34 (13%)
N3b	310 (18%)	279 (19%)	31 (12%)

Data are expressed as median (interquartile range) or number (%); the Mann–Whitney U test was used to evaluate differences in quantitative variables and the differences in proportions were evaluated using the chi-square test