Table 1.

Patient Characteristics

Variable	MSS/MSI-L	MSI-H
	(n = 15,079)	(n = 1,709)	p value
Demographics
Age (SD)	65.4 (13.6)	65.1 (15.4)	0.336
Female (%)	7,453 (49.4)	969 (56.7)	<0.001
Race
White	12,272 (81.4)	1,503 (87.9)	<0.001
Black	1,873 (12.4)	121 (7.1)
Other	934 (6.2)	85 (5.0)
Institution type
Community Cancer Program	1,243 (8.5)	133 (9.0)	<0.001
Comprehensive Community Program	6,158 (42.1)	674 (42.3)
Academic/Research	4,691 (32.1)	581 (36.5)
Integrated Network Cancer Program	2,528 (17.3)	193 (12.1)
Primary Payor
Not insured	581 (3.9)	50 (2.9)	0.269
Private insurance	5,825 (38.6)	648 (37.9)
Medicaid	887 (5.9)	90 (5.3)
Medicare	7,489 (49.7)	887 (51.9)
Other Government	141 9).9)	15 (0.9)
Unknown	156 (1.0)	19 (1.1)
Charlson-Deyo score
0	10,331 (68.5)	1,165 (68.2)	0.341
1	3,327 (22.1)	371 (21.7)
2	945 (6.3)	125 (7.3)
3+	476 (3.2)	48 (2.8)
Primary Tumor Site
Right colon	8,256 (54.8)	1,362 (79.7)	<0.001
Left colon/Rectosigmoid	6,823 (45.2)	347 (20.3)
Adjuvant chemotherapy	3,269 (21.7)	247 (14.5)	<0.001
T Stage
T3	12,906 (85.6)	1,466 (85.8)	0.830
T4	2,173 (14.4)	243 (14.2)
Lymphovascular Invasion
Absent	12,330 (81.8)	1,359 (79.5)	0.063
Present	1,980 (13.1)	247 (14.5)
Unknown	769 (5.1)	103 (6.0)
Perineural Invasion
Absent	13,505 (89.6)	1,542 (90.2)	0.108
Present	1,115 (7.4)	106 (6.2)
Unknown	459 (3.0)	61 (3.6)
Tumor Grade
Low Grade	13,032 (86.4)	1,088 (63.7)	<0.001
High Grade	1,774 (11.8)	585 (34.2)
Unknown	273 (1.8)	36 (2.1)
Positive Margins	874 (5.8)	102 (6.0)	0.773
< 12 Lymph Nodes	931 (6.2)	54 (3.2)	<0.001
High Risk Features	5,731/13,713 (41.8%)	818/1,537 (53.2%)	<0.001