Colorectal cancer is the most common cancers of the gastrointestinal tract malignancies and 2 takes place. Colorectal cancer incidence increases steadily after age 50 and reaches the highest level between the ages of 60-70. Approximately 20% occur before the age of 50. Young patients with ulcerative colitis or familial polyposis syndromes in the presence of colorectal cancer should be investigated.
Genetic factors in rectal cancer
Rectal cancers, as well as changes in chromosomes are available in all tumors. Many cancer cells, and atypical chromosomal configuration was observed distortion. There are studies showing that the increase in atypia worsened prognosis (1). Molecular genetic studies, early in the adenoma to carcinoma in turn, gene mutation and chromosome deletions has proven to be . Oncogene activation in familial polyposis syndromes and 6,17,18. chromosome deletions have been reported to be effective.
Polyposis is an autosomal dominant transition. Polyps begin to appear in the age of puberty. Gradually increase the number of polyps are initially sparse. Very high probability of developing cancer Preventive colectomy is performed.
Gardner syndrome, Turcot syndrome, Peutz-Jeghers syndrome and juvenile polyposis syndrome increases the risk of cancer.
The most important environmental risk factors, dietary habits. Fed fat-rich foods of animal societies, the incidence of colorectal cancer has increased. Shown to be effective, especially unsaturated fatty acids in the conversion of adenoma to cancer. Epithelial proliferation of anaerobic bacteria, increasing the microflora by affecting the oil accelerates the degradation products. Fecal bile acids is also a carcinogen, which is transformed into oil and lithocholic acid is metabolized by bacteria. Increasing the concentration of bile acid cholecystectomy, gastric surgery (resection of the terminal ileum) in such cases increases the risk of colorectal Ca.
Carotene, selenium, vitamins C and E, retinoids, reducing the risk of colorectal cancer and plant oils. Dietsel paucity of calcium intake and vitamin D deficiency increases the risk of Ca.