Critical prognostic value of the log odds of negative lymph nodes/tumor size in rectal cancer patients

Table 1 Baseline clinicopathological features of patients in the training cohort and validation cohort

Feature	Training cohort (n = 28875)	Validation cohort (n = 12325)
	n (%)	n (%)
Median age (IQR), yr	62 (53-72)	62 (53-71)
Median tumor size (IQR) mm	40 (27-55)	40 (26-55)
Median ELN count (IQR)	14 (10-20)	15 (10-20)
Median NLN count (IQR)	13 (9-18)	13 (9-18)
Median LONS (IQR)	-0.44 (-0.66 to -0.24)	-0.44 (-0.65 to -0.22)
Sex
Male	16998 (59.1)	7262 (58.9)
Female	11757 (40.9)	5063 (41.1)
TNM stage
I	7280 (25.3)	3132(25.4)
II	10355 (36.0)	4662 (36.2)
III	11120 (38.7)	4731 (38.4)
Differentiation
Poor	3741 (13.0)	1606 (13.0)
Moderate	21590 (75.1)	9169 (74.4)
High	2032 (7.1)	893 (7.2)
Unknown	1392 (4.8)	657 (5.3)
Preoperative radiotherapy
Yes	10385 (36.1)	4419 (35.9)
No	18730 (63.9)	7906 (64.1)
Chemotherapy
Yes	17688 (61.5)	7501 (60.9)
No	11067 (38.5)	4824 (39.1)
CEA
Normal	1056 (38.4)	4712(38.5)
High	6676 (23.2)	1736 (16.0)
Unknown	11023 (38.3)	4924 45.5)
N stage
N0	17635 (61.3)	7594 (61.6)
N1	7288 (25.3)	3036 (24.9)
N2	3832 (13.3)	1668 (13.5)
Histology type
Adenocarcinoma	27233 (94.7)	11640 (94.4)
MAC and SRCC	1522 (5.3)	5.6 (13.5)
Location
Rectum	18661 (64.9)	8044 (65.3)
Rectosigmoid junction	10094 (35.1)	4281 (34.7)
Race
White	23264 (80.9)	9962 (81.1)
Black	2357 (8.2)	1028 (8.3)
Others	3062 (10.6)	1299 (10.5)

CEA: Carcinoembryonic antigen; ELNs: Examined lymph nodes; IQR: Interquartile range; LONS: Log odds of negative lymph nodes/tumor size; MAC: Mucinous adenocarcinoma; NLNs: Negative lymph nodes; SRCC: Signet-ring cell carcinoma; TNM: Tumor-node-metastasis.