Metastatic lymph nodes and prognosis assessed by the number of retrieved lymph nodes in gastric cancer

Table 1 Clinical and pathological characteristics of patients in the training cohort and validation cohort

Characteristics	Training cohort	Validation cohort	P value
	n = 4968	n = 11154
Sex			< 0.001
Male	3634 (73.1)	7214 (64.7)
Female	1334 (26.9)	3940 (35.3)
Age (yr)			< 0.001
≤ 60	2845 (57.3)	3418 (30.6)
> 60	2123 (42.7)	7736 (69.4)
Tumor location			< 0.001
Upper third	552 (11.1)	3954 (35.4)
Middle third	811 (16.3)	1248 (11.2)
Lower third	3605 (72.6)	5952 (53.4)
Tumor size (mm)			< 0.001
≤ 50	3225 (64.9)	6813 (61.1)
> 50	1743 (35.1)	4341 (38.9)
Histological type			< 0.001
Well -moderately differentiated	2056 (41.4)	3402 (30.5)
Poorly-undifferentiated	2204 (44.4)	4197 (37.6)
Signet ring cell	397 (8.0)	1899 (17.0)
Others	311 (6.3)	1656 (14.8)
pT stage			< 0.001
pT1	1106 (22.3)	2746 (24.6)
pT2	745 (15.0)	1534 (13.8)
pT3	1583 (31.9)	4570 (41.0)
pT4	1534 (30.9)	2304 (20.7)
pN stage			< 0.001
pN0	2062 (41.5)	5411 (48.5)
pN1	927 (18.7)	2039 (18.3)
pN2	893 (18.0)	1768 (15.9)
pN3	1086 (21.9)	1936 (17.4)
pTNM			< 0.001
I	1445 (29.1)	3476 (31.2)
II	1383 (27.8)	3821 (34.3)
III	2140 (43.1)	3857 (34.6)
RLNs, median (range)	27 (1-95)	16 (1-90)
Chemotherapy			< 0.001
No/unknown	3769 (75.9)	5191 (46.5)
Yes	1199 (22.5)	5963 (53.5)

Tumor location, tumor size, pTNM stage, histological type and the number of removed lymph nodes were determined according to the postoperative pathology report. Statistically significant P values are in bold (P < 0.05).

RLNs: Retrieved lymph nodes.