Review on Gastric Cancer

Epidemiology of stomach cancer varies depending on several parameters including demographic, histological and geographic features. On the other hand, the measures of the associations of gastric cancer with putative risk factors are relatively robust with regard to these variations [1]. Each year approximately 990,000 people are diagnosed with gastric cancer worldwide, of whom about 738,000 die from this disease, making gastric cancer the 4th most common incident cancer and the 2nd most common cause of cancer death [2]. However, its incidence rates in different geographical regions are distinctly varied. Etiologically, gastric cancer is associated with Helicobacter pylori infection, nutritional and lifestyle factors, and genetics [3,4]. This review provides an update of the current trends of gastric cancer. Overall, in most developed countries, its incidence has decreased substantially in the past five decades, with the disorder now the 14th most common neoplasm in the USA. However, in many developing countries, the incidence of gastric cancer has increased during the same period. In the Middle East, the incidence varies from high in Iran (age-standardized incidence rate 26·1 per 100 000 individuals per year) to low in Israel (12·5 per 100 000 per year) and Egypt (3·4 per 100 000 per year).Gastric cancer is the most common malignant disease in Iran and Oman [5-7].