Table II.

Cox regression analyses of 3-year overall survival.

	Univariate analysis			Multivariate analysis
Variables	HR	95% CI	P-value	HR	95% CI	P-value
Age, years
≥85 vs. <85	1.76	0.67–4.58	0.24
Gender
Male vs. female	1.60	0.66–3.86	0.29
Charlson comorbidity index
≥2 vs. 0, 1	1.36	0.45–4.07	0.57
ASA physical status
III, IV vs. I, II	1.72	0.71–4.16	0.22
Tumor site
Rectum vs. colon	0.86	0.31–2.39	0.78
Stage
III vs. I, II	4.47	1.82–10.95	0.001	4.31	1.76–10.58	0.001
Histology
Undifferentiated vs. differentiated	3.16	0.92–10.80	0.066
BMI
Underweighta vs. non-underweightb	2.82	1.15–6.91	0.023	2.65	1.08–6.50	0.033

^aBMI<18.5 kg/m².

^bBMI≥18.5 kg/m². HR, hazard ratio; CI, confidence interval; ASA, American society of anesthesiologists; BMI, body mass index.