Table 1.

Demographics and clinicopathologic characteristics of the SEER dataset (training set) and Renji dataset (validation set)

Demographic or clinicopathologic characteristic	SEER dataset (N = 1753)				Renji dataset (N = 239)
	No. of patients	%	OS (months)		No. of patients	%	OS (months)
			Median	95% CI			Median	95% CI
Sex
Male	527	30	22	19–27	80	33	18	11–38
Female	1226	70	25	22–28	159	67	21	15–32
Age, years
≥ 70	771	44	18	16–21	99	41	21	16–38
< 70	982	56	30	26–35	140	59	16	13–37
Resection type
Radical resection	384	22	21	17–26	196	82	28	20–45
Palliative resection	1369	78	25	23–29	43	18	7	4–9
Tumor histology
Papillary histology	114	6	89	78–NA	7	3	NA	7–NA
Squamous histology	80	5	10	9–17	18	8	9	5–NA
Adenocarcinoma and others	1559	89	23	21–25	214	89	21	15–28
Tumor grade
I	237	13	40	33–88	23	9.6	NA	45–NA
II	788	45	32	27–36	158	66	17	14–28
III	679	39	15	14–18	57	24	14	8–23
IV	49	3	10	6–17	1	0.4	NA	NA
Tumor size, cm
< 3	763	44	35	30–41	83	35	33	17–NA
3–5	534	30	21	18–25	87	36	26	17–42
5–10	393	22	15	14–19	60	25	9	8–17
≥ 10	63	4	10	8–14	9	4	7	6–NA
Tumor number
Single tumor	1647	94	22	20–25	182	76	28	22–45
Multiple tumors	106	6	57	37–72	57	24	7	6–10
Pathologic T category
T1	214	12	90	66–112	31	13	NA	45–NA
T2	808	46	42	35–53	31	13	40	15–NA
T3	661	38	13	12–14	151	63	17	14–27
T4	70	4	8	7–14	26	11	5	3–10
Pathologic N category
N0	877	50	55	45–72	132	55	56	31–NA
N1	786	45	14	13–16	72	30	12	9–15
N2	90	5	14	10–17	35	15	6	5–9
Pathologic M category
M0	1492	85	31	28–35	182	76	32	23–56
M1	261	15	9	8–10	57	24	7	6–9
8th AJCC stage
I	180	10	99	87–139	29	12	NA	56–NA
II	408	23	90	78–127	18	8	NA	26–NA
III	855	49	19	17–20	113	47	28	21–56
IV	310	18	9	8–10	79	33	7	6–9

NA not available