Table 3. Impact of DM on outcome of overall survival of stage 1 to 3 colon cancer patients according to their BMI, TNM stage, age and site of cancer (proximal vs distal).

	Non DM	DM	Ptrend	Pinteraction
Risk of overall survival
Male
No at risk/events	1091/234	181/49
MV adjusted (95% CI)	1.00 (Ref)	1.45 (1.02–2.06)	0.038
Female				0.828
No at risk/events	804/154	107/30
MV adjusted (95% CI)	1.00 (Ref)	1.48 (0.96–2.30)	0.075
BMI specific effects of DM ?
BMI <23 kg/m2
No at risk/events	877/186	109/29
MV adjusted (95% CI)	1.00 (Ref)	1.48 (1.06–2.05)	0.02
BMI >23 kg/m2				0.672
No at risk/events	828/141	153/36
MV adjusted (95% CI)	1.00 (Ref)	1.52 (1.04–2.21)	0.031
Stage specific effects of DM
TNM Stage I/II
No at risk/events	1184/174	180/43
MV adjusted (95% CI)	1.00 (Ref)	1.38 (1.05–1.81)	0.019
TNM Stage III				0.369
No at risk/events	711/214	108/36
MV adjusted (95% CI)	1.00 (Ref)	1.25 (0.84–1.85)	0.269
Age specific effects of DM
Age <60 years
No at risk/events	977/145	89/20
MV adjusted (95% CI)	1.00 (Ref)	2.04 (1.17–3.54)	0.012
Age≥60 years				0.169
No at risk/events	918/243	199/59
MV adjusted (95% CI)	1.00 (Ref)	1.43 (1.04–1.96)	0.026
Site Specific effects of DM *
Proximal Colon
No at risk/events	798/170	128/39
MV adjusted (95% CI)	1.00 (Ref)	2.08 (1.38–3.13)	>0.001
Distal Colon				0.108
No at risk/events	1073/215	153/37
MV adjusted (95% CI)	1.00 (Ref)	1.34 (0.92–1.96)	0.12

DM: Diabetes mellitus, CI: Confidence Interval, BMI: Body mass index, MV: Multivariate, MV adjusted: Gender, BMI, TNM stage, family history of colorectal cancer (yes or no), Adjuvant therapy (No, Chemotherapy only, Radiation therapy only, Chemotherapy and radiation therapy together), the year of surgery,

^?216 case were not included due to missing BMI information,

^*31 cases were not included due to missing information on the site specific location (proximal vs distal).