Dose surgical sub-specialization influence survival in patients with colorectal cancer?

Table 1 Basic demographic data for the study groups of patients with colorectal cancer

Number	362	137	475
Mean age-years	69 (± 12)	70 (± 11)	69 (± 13)
Age range-years	29 to 93	38 to 93	32 to 95
Sex ration M:F	1.3:1	1.4:1	1.4:1
ASA score of 3 or 4	40%	39%	22%
Elective vs emergency	319 vs 43	112 vs 25	394 vs 81
procedures	(88% vs 12%)	(78% vs 18%)	(79% vs 17%)
Curative vs palliative	264 vs 80	101 vs 23	366 vs 85
pesections	(73% vs 22%)	(74% vs 17%)	(77% vs 18%)
No surgery	18 (5%)	13 (9%)	24 (5%)
Colon cancer	170 (47%)a	90 (66%)	314 (66%)
Rectal cancer	192 (53%)b	47 (34%)	161 (34%)
Adjuvant chemotherapy	116 (32%)c	19 (14%)	17 (4%)
Adjuvant radiotherapy	65 (18%)d	9 (7%)	14 (4%)
Mean follow-up-years	2.75 (± 1.2)e	4.5 (± 1.4)	5.1 (± 4.5)
Max follow-up-years	6.8	6.9	13.9

^aP < 0.05,

^bP < 0.05,

^cP < 0.05,

^dP < 0.05,

^eP < 0.05, ^fP < 0.05 vs the other two group.

Table 2 Staging information for colorectal cancers for the study groups

Stage	Colorectal group number (%)	General surgical group number (%)	Historical group number (%)
Stage I	81 (22%)a	9 (7%)	57 (12%)
Stage II	95 (26%)b	53 (39%)	159 (33%)
Stage III	91 (25%)	41 (30%)	146 (31%)
Stage IV	91 (25%)	29 (21%)	106 (22%)
Stage unknown	4 (1%)	4 (3%)	7 (2%)

^aP < 0.05,

^bP < 0.05 vs the other two group with the Chi-square test.

Table 3 A comparison of the overall 5 year survival based on stage for the study groups

Stage	Colorectal group	General surgical group	Historical group
I	90%a	67%	72%
II	62%	57%	58%
III	60%b	46%	34%
IV (2 year survivals)	22%	21%	19%

^aP < 0.05,

^bP < 0.05 vs the other two group.

Table 4 Cox survival regression analysis of independent predictors of the overall survival in the 974 patients with colorectal cancer

Independent variables	P	Hazard ratio	95% Confidence interval
Age	0.15	1.011	1.002-1.020
ASA score	< 0.0001	1.477	1.29-1.69
Adjuvant chemotherapy	0.047	0.634	0.405-0.993
Stage I	< 0.0001	0.211	0.107-0.418
Stage II	0.003	0.397	0.214-0.738
Stage III	0.19	0.665	0.358-1.237
Stage IV	0.009	2.27	1.229-4.186
Colorectal surgical unit vs control	0.0005	0.667	0.531-0.837