Castomach..ppt

Ca stomach Change in tumor location From body and antrum to proximal stomach and oesophagogastric junction Incidence in Hong KongHong Kong Cancer Registry 2009 data Male Crude incidence 20.8 per 100 000 Crude mortality 12.6 per 100 000 Female Crude incidence 10.7 per 100 000 Crude mortality 6.6 per 100 000 Risk factors Helicobacter pylori acid hyposecretory conditions Dietary conditions Smoking hereditary nonpolyposis colorectal cancer familial polyposis coli CDH-1 gene mutation Helicobacter pylori only a small minority of infected subjects develop gastric cancer (estimated at approximately three cases per year for every 10,000 infected persons). Initiation of the carcinogenesis process has been linked to oxidative stress brought about by inducible nitric oxide synthase (iNOS) that is produced by inflammatory cells responding to H. pylori infection. Nitric oxides are mutagenic and may induce abnormalities in the DNA of epithelial cells. Less salty Need less salt for food preservation High salt intake?damages stomach mucosa and increases the susceptibility to carcinogenesis in rodents Refrigeration also allowed for fresh food and vegetables to be more readily available, which may be a valuable source of antioxidants Nitroso compounds? Dietary nitrates (natural components of foods like vegetables and potatoes and food additive in some cheeses and cured meats ) are absorbed in the stomach and secreted in saliva in a concentrated form where they are reduced to nitrites by oral bacteria. Elevated levels of gastric nitrite, particularly in a high pH environment, have been linked to advanced precancerous gastric lesions endogenous production of N-nitroso compounds was significantly associated with non-cardia cancer risk (hazard ratio [HR] 1.42, 95% CI 1.14-1.78) Diets that are high in fried food, processed meat, and fish and alcohol (and low in vegetables, fruits, milk, and vitamin A) have been associated with an increased risk of gastric carcinoma in several