IT O R

Gastric cancer is one of the most prevalent cancers worldwide, ranking fourth after lung, breast and colorectal cancers, and it is the second cause of cancer death. The majority of cases occur in developing countries and are more common in males, irrespective of age and geographic area. In Portugal it ranks fifth in cancer deaths and its inci-dence is the highest in Western Europe. The most common type of gastric cancer is adeno-carcinoma, whose prevalence is related to male gender, increasing age and high prevalence regions, indicating environmental factors as risk factors for the disease. The accepted model for development of this type of cancer in-volves a cascade of premalignant conditions occurring over several years, due to environmental and host factors, which might progress to premalignant lesions (e.g. dysplasia) an