Risk factors for the development of colorectal carcinoma: A case control study from South India

Table 1 Socio demographic details of study population, n (%)

Variable	Cases	Controls
Age (yr)
< 40	9 (9.6)	7 (7.4)
40-49	21 (22.3)	18 (19.1)
50-59	28 (29.8)	29 (30.9)
60-69	30 (31.9)	32 (34)
≥ 70	6 (6.4)	8 (8.5)
Educational status
Never attended school	37 (39.4)	33 (35.1)
1-4	23 (24.5)	34 (36.2)
5-7	15 (16)	10 (10.6)
8-10	14 (14.9)	9 (9.6)
11-12	1 (1.1)	6 (6.4)
Graduation	4 (4.3)	2 (2.1)
Occupation
Non worker	23 (24.5)	19 (20.2)
Skill I	44 (46.8)	59 (62.8)
Skill II	25 (26.6)	16 (17)
Skill III	2 (2.1)	0
PCI in indian rupees/mo
Class I > 4400	1 (1.1)	0
Class II 2200-4399	1 (1.1)	2 (2.1)
Class III 1320-2199	5 (5.3)	6 (6.4)
Class IV 660-1319	34 (36.2)	38 (40.4)
Class V < 660	53 (56.4)	48 (51.1)

PCI: Per Capita Income (after adjusting for Consumer Price Index of 2011).

Table 2 Frequency of food intake among cases and controls, n (%)

Food item		Never or hardly ever	Once a month	2-3 times/mo	Once a week	2-3 times/wk	4-6 times/wk	Once a day	Total
Egg	Case	7 (7.4)	17 (18.1)	6 (6.4)	28 (29.8)	21 (22.3)	7 (7.4)	8 (8.5)	94
	Control	8 (8.5)	36 (38.3)	10 (10.6)	27 (28.7)	8 (8.5)	-	5 (5.3)	94
Chicken	Case	13 (13.8)	31 (33)	9 (9.6)	36 (38.3)	5 (5.3)	-	-	94
	Control	12 (12.8)	45 (47.9)	14 (14.9)	19 (20.2)	4 (4.3)	-	-	94
Mutton	Case	23 (24.5)	40 (42.6)	4 (4.3)	25 (26.6)	1 (1.1)	1 (1.1)	-	94
	Control	44 (46.8)	42 (44.7)	3 (3.2)	4 (4.3)	1 (1.1)	-	-	94
Fish	Case	26 (27.7)	49 (52.1)	2 (2.1)	6 (6.4)	10 (10.6)	1 (1.1)	-	94
	Control	27 (28.7)	61 (64.9)	1 (1.1)	2 (2.1)	1 (1.1)	2 (2.1)	-	94
Beef	Case	68 (72.3)	1 (1.1)	1 (1.1)	18 (19.1)	6 (6.4)	-	-	94
	Control	81 (86.2)	6 (6.4)	-	7 (7.4)	-	-	-	94
Pork	Case	81 (86.2)	9 (9.6)	1 (1.1)	2 (2.1)	1 (1.1)	-	-	94
	Control	87 (92.6)	5 (5.3)	-	2 (2.1)	-	-	-	94
Fried foods	Case	3 (3.2)	32 (34.0)	6 (6.4)	35 (37.2)	18 (19.1)	-	-	94
	Control	5 (5.3)	45 (47.9)	14 (14.9)	28 (29.8)	2 (2.1)	-	-	94
Fruits	Case	32 (34.0)	37 (39.4)	7 (7.4)	6 (6.4)	5 (5.3)	3 (3.2)	4 (4.3)	94
	Control	36 (38.3)	23 (24.5)	14 (14.9)	13 (13.8)	3 (3.2)	-	5 (5.3)	94
Vegetables	Case	-	-	-	-	13 (13.8)	7 (7.4)	74 (78.7)	94
	Control	-	-	-	-	2 (2.1)	8 (8.5)	84 (89.4)	94
Coffee	Case	81 (86.2)		-	-	-	-	13 (13.8)	94
	Control	87 (92.6)	-	-	-	-	-	7 (7.4)	94
Tea	Case	20 (21.2)		-	-	-	-	74 (78.7)	94
	Control	11 (11.7)	-	-	-	-	-	83 (88.3)	94

Table 3 Colorectal carcinoma risk associated with individual dietary item

Food item			Adjusted OR (CI)	P value
Egg	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	1.6 (0.85-3.33)	0.133
	Tertile 3	> 2-3 times a week	5.1 (2.26-11.36)	0.001
Chicken	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	0.6 (0.25-1.51)	0.297
	Tertile 3	Once a week	1.6 (0.64-4.19)	0.297
Mutton	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	1.8 (0.93-3.45)	0.070
	Tertile 3	More than 2-3 times a month	7.4 (2.93-3.45)	0.001
Fish	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	0.8 (0.44-1.60)	0.588
	Tertile 3	More than 2-3 times a month	3.2 (1.13-9.53)	0.028
Beef	Tertile 1	-	-	-
	Tertile 2	Never or hardly ever	1
	Tertile 3	More than once a month	2.3 (0.13-4.99)	0.237
Fruits	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	1.8 (0.89-3.64)	0.099
	Tertile 3	More than 2-3 times a month	0.8 (0.39-1.68)	0.540
Vegetables	Tertile 1	2-3 times a week	1
	Tertile 2	Once a day	0.4 (0.19-1.00)	0.050
	Tertile 3	-	-	-
Fried foods	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	0.61 (0.21-1.74)	0.350
	Tertile 3	2-3 times a month	2.52 (1.35-4.70)	0.004

Table 4 Association of variables with colorectal carcinoma, n (%)

Variable	Cases	Controls	OR (CI)
Type of oil
Refined	29 (30.9)	22 (23.4)	1
Groundnut	15 (16)	42 (44.7)	0.271 (0.12-0.61)
Palm	50 (53.2)	30 (31.9)	1.264 (0.62-2.59)
Type of food
Moderate spicy	73 (77.7)	82 (87.2)	1
Very spicy	21 (22.3)	12 (12.8)	1.97 (0.91-4.28)
Smoking status
Non-smoker	74 (78.7)	75 (79.7)	1
< 10 pack years	3 (3.19)	5 (5.31)	0.60 (0.14-2.63)
10-20 pack years	5 (5.31)	10 (10.6)	0.50 (0.16-1.55)
> 20 pack years	12 (12.8)	4 (4.3)	3.04 (0.93-9.85)
Alcohol use
Non users	68 (72.3)	74 (78.7)	1
Grade I (< 39.9 g/d)	19 (20.2)	10 (10.6)	2.06 (0.89- 4.75)
Grade II (40-59.9 g/d)	4 (4.2)	6 (6.3)	0.72 (0.19-2.68)
Grade III (> 60 g/d)	3 (3.2)	4 (4.2)	0.81 (0.17-3.78)
Physical activity (METs/wk)
Low (< 600)	18 (19.1)	24 (25.5)	1
Moderate (600-3000)	51 (54.3)	44 (46.8)	1.54 (0.74-3.21)
High (> 3000)	25 (26.6)	26 (27.7)	1.28 (0.56-2.91)
BMI (kg/m2)
< 18.5 (underweight)	19 (20.2)	10 (10.6)	1
18.5-22.99 (normal)	47 (50)	57 (60.6)	0.43 (0.18-1.02)
23-24.99 (over weight)	14 (14.9)	17 (18.1)	0.43 (0.15-1.22)
≥ 25 (obese)	14 (14.9)	10 (10.6)	0.73 (0.24-2.24)
Diabetes mellitus
No	73 (53.3)	67 (46.7)	1
yes	21 (41.2)	30 (58.8)	1.62 (0.85-3.12)

METs/wk: Metabolic equivalents minutes per week; BMI: Body mass index.

Table 5 Factors independently associated with colorectal carcinoma

Food item			Adjusted OR (CI)	P value
Mutton	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	2.62 (0.08-6.33)	0.137
	Tertile 3	> 2-3 times a month	5.41 (1.55-19.05)	0.008
Egg	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	1.54 (0.63-3.70)	0.340
	Tertile 3	> 2-3 times a week	3.67 (1.23-9.35)	0.013
Fried foods	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	0.76 (0.22-2.54)	0.655
	Tertile 3	> 2-3 times a month	2.03 (0.95-4.43)	0.060
Fish	Tertile 1	Never or hardly ever	1
	Tertile 2	Once a month	0.02 (0.08-0.58)	0.195
	Tertile 3	> 2-3 times a month	0.39 (0.09-1.62)	0.237
Type of oil	Refined	NA	1
	Ground nut	NA	0.4 (0.15-1.00)	0.068
	Palm	NA	1.6 (0.75-4.04)	0.240