Table 1.

Classification of risk factors associated with CRC in terms of relative risk

Risk factors	Category at risk	RR	Ref.
Age	Patients who have proximal advanced cancer	1.3	[6]
Socio-economic status	Patients with low socioeconomic status	2.88/2.42*	[9]
Personal history of polyps	Patients with distal hyperplastic polyps	2.6	[6]
	Patients with distal tubular polyps	4.0
	Patients with distal advanced cancer	6.7
Personal history of CRC	Patients with 1-2 tubular adenomas <1cm	1.92	[13]
	Patients with 3 or more tubular adenomas <1 cm	5.01
	Patients with tubular adenomas > or = 1cm	6.4
	Patients with villous adenomas	6.05
	Patients with high dysplasia adenomas	6.87
Family history of CRC and colorectal adenomas	Patients with first-degree relatives of rectal cancer	1.89	[20]
	Patients with first-degree relatives with CRC	2.25
	Patients with a parent with CRC	2.26
	Patients with first-degree relatives with colonic cancer	2.42
	Patients with brother / sister with a common parent having CRC	2.57
	Patients with relatives diagnosed with CRC before the age of 45 years	3.87
	Patients with more than one relative with CRC	4.25
Personal history of inflammatory bowel disease	Patients with CRC and UC	1 – 2.75	[25]
Diet with high content of red meat and fats	Patients having a diet rich in red meat	1.17 / 1.83†	[31]
Alcohol	Consummator	1.56	[38]
Smoking	Smokers	1.20 / 1.38	[40]
Menopause status	Pre menopause women	1.61	[47]
Sedentary behaviour	Sedentary patients	1.61	[41]
Obesity	Patients with BMI> or = 40	2.39 / 1.49†	[44]
Low-penetrance polymorphisms	APC I1307K	1.5 – 2.2	[64]
	TGFβR1*6Ala	1.2	[65]
	HRAS1	2.5	[58]

Obs: * Estimated risk for colonic and rectal cancer; † Estimated risk for men and women