The cause of colorectal cancer.

摘要: Abstract Colorectal cancer continues to represent one of the major causes cancer-related morbidity in all western countries. A review has been made main aetiological factors which have related colorectal development with particular attention being focused on: a) new advancements molecular biology, and b) interaction between genetic predisposition environmental factors. Worldwide, approximately 900,000 cases malignancies diagnosed 1996 this accounts for 8.5% cancer. Crude incidence rates range from 0.6 – 5.0 cases/100,000/year Senegal India 50–70 developed Environmental factors, such as meat, saturated fat, low physical activity, obesity, smiking, alcoholic beverages, inflammatory bowel diseases seem increase risk In contrast, fruit, vegetables, fibre, antioxidant vitamins, calcium, folate, exercise non-steroidal anti-inflammatory drugs show a orotective effect. For some these basis their mechanism action begins be elucidated. develops benign precursors, adenomatous polyps; there is extensive evidence that polyps transform into stepwise manner, several abnormalities (mutations oncogenes, inactivation tumour suppressor genes microsatellite instability) accompany and, somehow, determine tumourigenesis. Two Hereditary Cancer syndromes — Familial Adenomatous Polyposis Non polyposis described characterized at levels; it estimated inherited conditions might account up 5% large malignancies. remains undefined presumably due multifactorial inheritance. Recently, identified germline mutations (such l1307K APC gene) fraction familial cases, least populations. At variance many other tumours, aetiology pathogenesis partially clarified, so we are now position take preventive measures design surveillance programmes lead certain reduction mortality. However, since strictly modern customs lifestyle, they will difficult eradicate; awareness should stimulate further investigations exciting field research.