Table 1.

Comparison of the training and validation datasets for rectal cancer patients.

	Rectum
	Training	Validation	p-value
Total Number of Patients	4059	3069	-
Median Age (range)	60 (18 – ≥90)	60 (19 – ≥90)	0.437
Charlson-Deyo Score			0.984
0	3176 (78.2%)	2404 (78.3%)
1	681 (16.8%)	511 (16.7%)
2	130 (3.2%)	102 (3.3%)
≥3	72 (1.8%)	52 (1.7%)
Grade Differentiation			0.172
Well	269 (6.6%)	212 (6.9%)
Moderate	2949 (72.7%)	2286 (74.5%)
Poor	776 (19.1%)	525 (17.1%)
Undifferentiated	65 (1.6%)	47 (1.5%)
Highest CEA Level		46	0.282
≤6ng/mL	1096 (27.0%)	834 (27.2%)
6.1–28.9ng/mL	1177 (29.0%)	839 (27.3%)
29–97.9ng/mL	768 (18.9%)	573 (18.7%)
≥98ng/mL	1018 (25.1%)	823 (26.8%)
Liver Metastasis	3299 (81.3%)	2503 (81.6%)	0.763
Lung Metastasis	1506 (37.1%)	1156 (37.7%)	0.626
Bone Metastasis	344 (8.5%)	229 (7.5%)	0.119
Brain Metastasis	68 (1.7%)	48 (1.6%)	0.713
Peritoneal Metastasis	1050 (25.9%)	844 (27.5%)	0.122
Primary Site Resected	1565 (38.6%)	1158 (37.7%)	0.478
Non-Primary Site Resected	692 (17.0%)	567 (18.5%)	0.118
Median # of Positive LNs (range)	0 (0 – 50)	0 (0 – 37)	0.081
Any Chemotherapy	3372 (83.1%)	2647 (86.2%)	<0.001
Any Radiation Therapy	1732 (42.7%)	1248 (40.7%)	0.089