Cancer Of. the Colon • Major public health problem • In developed countries • epidemiologists, molecular biologists, nutritionists, • gastroenterologists, prevention experts, surgeons, radiation • therapists, nurses, medical oncologists,
Gross Anatomy • Colon and the rectum • intraperitoneal or extraperitoneal. • rectal cancers, which usually have no serosal covering and are surrounded by fat, bone, nerves, blood vessels, and viscera
Gross Anatomy • The cecum, transverse colon, and sigmoid loop are the intraperitoneal portions of the colon • Ascending colon, descending colon, splenic and hepatic flexures, sigmoid colon -surface in the retroperitoneum.
Epidemiology • Third in frequency in men and second in women • fourth leading cause of cancer mortality • better prognosis than more common cancers. • 5-year survival rate of 41% to 42%
Etiology • Genetic change in the epithelial cells of the colonic mucosa. • Mutagen exposure and genetic constitution • Reduced glutathione S-transferase (GSH transferase), DT-diaphorase, and Nacetyltransferase..
Fecal Mutagens • fecapentaenes, 3-ketosteroids, and heterocyclic amines • Changes in the fecal microflora • Altering extracellular superoxide formation. • Intake of antioxidants • Changes in intestinal transit
Etiology • • • • • • •
Meat Intake Bile Acids Vitamin and Mineral Intake Fecal pH tobacco and alcohol use Dietary Factors Hormone Replacement in Women
Clinical Risk Factor