Contemporary, national patterns of surgery after preoperative therapy for stage II/III rectal adenocarcinoma

Table 3 Unadjusted (univariate) and adjusted (multivariate) factors associated with overall survival

Variable	n	Events	5-yr survival% (95%CI)	Cox univariate HR (95%CI)	Cox univariate score P value	Cox multivariate HR (95%CI)	Cox multivariate likelihood ratio P value (n = 15618)
Age at diagnosis	27114	5281 (19%)	73.3 (72.6, 74.0)	1.03 (1.03, 1.04)	< 0.0001	1.02 (1.02, 1.02)	< 0.0001
Sex					< 0.0001		< 0.0001
Female	10502	1869 (18%)	75.5 (74.4, 76.6)
Male	16612	3412 (21%)	71.9 (70.9, 72.8)	1.19 (1.13, 1.26)		1.23 (1.14, 1.32)
Charleson comorbidity score					< 0.0001		< 0.0001
0	20949	3656 (17%)	75.7 (74.9, 76.5)
1	4792	1202 (25%)	67.4 (65.6, 69.1)	1.43 (1.34, 1.53)		1.25 (1.14, 1.36)
2+	1373	423 (31%)	58.5 (55.0, 62.0)	2.00 (1.81, 2.22)		1.59 (1.38, 1.82)
Race					< 0.0001		0.3372
Black	2307	508 (22%)	69.7 (67.1, 72.2)	1.18 (1.08, 1.29)		1.04 (0.92, 1.19)
Other	1542	246 (16%)	76.6 (73.6, 79.5)	0.85 (0.74, 0.96)		1.01 (0.85, 1.20)
White	23091	4498 (19%)	73.4 (72.7, 74.2)
Insurance status					< 0.0001		< 0.0001
Insurance status unknown	382	64 (17%)	71.8 (64.8, 78.8)	1.46 (1.14, 1.88)		0.93 (0.62, 1.39)
Medicare/medicaid/other government	11607	3039 (26%)	64.8 (63.6, 66.0)	2.12 (2.01, 2.25)		1.33 (1.22, 1.46)
Not insured	1357	294 (22%)	71.1 (67.9, 74.2)	1.61 (1.42, 1.82)		1.14 (0.97, 1.33)
Private insurance/managed care	13768	1884 (14%)	80.8 (79.9, 81.7)
Living location					0.0407		0.3867
Metropolitan	21521	4134 (19%)	73.7 (72.9, 74.5)
Rural	611	117 (19%)	72.9 (68.2, 77.6)	1.01 (0.84, 1.22)		0.85 (0.67, 1.08)
Urban	4344	900 (21%)	71.7 (69.9, 73.5)	1.10 (1.02, 1.18)		0.98 (0.89, 1.08)
Facility type					< 0.0001		0.5531
Academic/research program	10235	1850 (18%)	75.4 (74.2, 76.5)
Community cancer program	1624	384 (24%)	67.4 (64.4, 70.5)	1.37 (1.22, 1.53)		1.00 (0.86, 1.17)
Comprehensive community cancer program	10158	2097 (21%)	71.6 (70.4, 72.8)	1.17 (1.10, 1.25)		1.06 (0.98, 1.15)
Integrated network cancer program	3719	761 (20%)	72.2 (70.2, 74.1)	1.17 (1.07, 1.27)		1.04 (0.93, 1.16)
Facility geographic region					0.0008		0.0971
Midwest	7378	1455 (20%)	73.6 (72.2, 74.9)	0.91 (0.85, 0.97)		0.926 (0.846, 1.014)
Northeast	5058	967 (19%)	74.1 (72.4, 75.7)	0.87 (0.80, 0.94)		0.912 (0.820, 1.014)
South	9090	1885 (21%)	71.2 (69.9, 72.4)
West	4210	785 (19%)	74.0 (72.2, 75.8)	0.89 (0.82, 0.97)		0.878 (0.783, 0.986)
Pathological stage					< 0.0001		< 0.0001
0	782	66 (8%)	89.2 (86.4, 92.1)
1	5631	604 (11%)	84.8 (83.5, 86.1)	1.277 (0.990, 1.646)		1.11 (0.84, 1.46)
2	6861	1399 (20%)	72.1 (70.6, 73.5)	2.48 (1.94, 3.17)		1.97 (1.50, 2.57)
3	8247	2338 (28%)	61.6 (60.2, 63.1)	3.74 (2.93, 4.77)		3.32 (2.55, 4.33)
4	136	82 (60%)	25.1 (15.6, 34.6)	10.93 (7.90, 15.11)		8.70 (5.97, 12.67)
Chemotherapy (multi or single agent)					< 0.0001		0.001
Multiagent chemotherapy	10043	1616 (16%)	77.9 (76.8, 79.0)
Single-agent chemotherapy	12445	2467 (20%)	72.6 (71.5, 73.6)	1.31 (1.23, 1.39)		1.14 (1.06, 1.24)
Chemotherapy sequence					< 0.0001		< 0.0001
Chemotherapy after surgery	2387	543 (23%)	71.7 (69.4, 74.0)	1.12 (1.02, 1.23)		0.89 (0.75, 1.06)
Chemotherapy before surgery	14351	2849 (20%)	72.6 (71.6, 73.6)
Chemotherapy before and after surgery	8128	1134 (14%)	79.7 (78.5, 80.9)	0.67 (0.63, 0.72)		0.73 (0.67, 0.79)
Radiation sequence					< 0.0001		0.3489
Radiation after surgery	1934	463 (24%)	70.5 (68.0, 73.1)	1.30 (1.18, 1.43)		0.92 (0.77, 1.10)
Radiation before surgery	22529	4054 (18%)	75.0 (74.2, 75.7)
Surgery type					< 0.0001		< 0.0001
Local excision	953	249 (26%)	65.0 (61.0, 69.1)	1.62 (1.42, 1.84)		1.26 (0.94, 1.68)
TME with sphincter preservation	18237	3107 (17%)	76.4 (75.6, 77.2)
TME without sphincter preservation	7924	1925 (24%)	67.5 (66.1, 68.8)	1.44 (1.36, 1.53)		1.30 (1.20, 1.40)
Surgical approach					< 0.0001		< 0.0001
Laparoscopic	8510	1400 (16%)	76.8 (75.5, 78.0)	0.77 (0.72, 0.82)		0.85 (0.78, 0.93)
Open	14207	3300 (23%)	70.7 (69.8, 71.7)
Robotic	4397	581 (13%)	75.7 (73.5, 77.8)	0.72 (0.66, 0.79)		0.82 (0.73, 0.92)
Tumor grade					< 0.0001		< 0.0001
Other (ND/UNK/NA/high grade dysplasia)	3918	594 (15%)	77.3 (75.5, 79.2)	0.87 (0.80, 0.95)		0.99 (0.88, 1.11)
Poor/undifferentiated	3023	1004 (33%)	58.9 (56.7, 61.1)	1.97 (1.84, 2.11)		1.67 (1.52, 1.83)
Well/moderate differentiation	20173	3683 (18%)	74.8 (74.0, 75.6)
Residual tumor					< 0.0001		< 0.0001
R0	24991	4432 (18%)	75.5 (74.8, 76.2)
R1	932	414 (44%)	44.5 (40.4, 48.6)	3.03 (2.74, 3.36)		2.23 (1.96, 2.54)
R2	869	347 (40%)	46.5 (42.2, 50.9)	2.76 (2.47, 3.08)		1.99 (1.71, 2.30)
12 or more lymph nodes examined					< 0.0001		< 0.0001
No	8705	1919 (22%)	70.9 (69.6, 72.1)	1.19 (1.12, 1.25)		1.26 (1.17, 1.36)
Yes	18176	3317 (18%)	74.5 (73.6, 75.4)

TME: Total mesorectal excision.