In a review of colorectal cancer Cunningham et al March 20th Lancet 2010 discuss the risk factors in developing cancer of the colon. One million individuals world wide will develop cancer of the colon.
They state that most cases arise sporadically. Risk factors include age, male sex, previous colonic polyps, and environmental factors ( e.g. red meat, high fat diet, inadequate intake of fibre , obesity , sedentary life style, diabetes mellitus, smoking and high consumption of alcohol) . Inflammatory bowel disease ( ulcerative colitis ands Crohn’s) accounts for two thirds of the incidence , 18 % after 30 years ) .
In general, cancer of the colon is associated with chromosomal ( 85% ) and micro satellite instability ( 15%).Micro satellite is a repeating DNA segment.
Hereditary cause play a small but significant role. A germline mutation in a mismatch repair gene ( most commonly MLH1, MSH2, MSH6 )and is associated with cancer of the colon in a family.
Cunningham et al Colorectal Cancer 2010 Lancet vol 375 p 1030-103
- Martin Eastwood