Gastric cancer

Gastric cancer

    * Introduction
    * Causes
    * Signs and symptoms
    * Diagnosis
    * Treatment
Gastric cancer is a malignancy with a starting point in the gastric mucosa, representing one of the most common sites of visceral malignancies, ranking it the second most common after lung neoplasm.
Spreading the world is variable, the most met in Japan, China, Eastern Europe. The incidence is higher in males, and the average age at occurrence is 70 years for men and 75 women. Areas with high mortality in Rumania are the western and eastern Transylvania, Bucharest and Teleorman.
Many experimental studies, epidemiological and clinical intervention demonstrates the many risk factors that can act simultaneously or sequentially. Food is one of the most important environmental factors involved in the pathogenesis of gastric cancer. Consumption of food preserved by drying and smoke, excessive salt, turning nitrates into nitrites by the formation of N-nitroso compounds and nitrosamines-nitrosamide, decreased daily intake of dietary fiber, low intake of selenium are sources of carcinogens.
Initial symptoms are nonspecific, it is often suggestive of peptic ulcer dyspepsia. Patient and doctor tend to not give due weight to symptoms and treat them as an acidic condition. Later, the feeling of early satiety may occur if the cancer blocks the pyloric region or if the stomach secondary unwind silence no longer plastic. Losing weight, usually due to diet, haematemesis and melena are rare, but occult bleeding secondary anemia is often present.
Patients suspected of gastric cancer requires endoscopy, multiple biopsies and cytologic examination. The neoplasm requires the examination revealed that the thoracic and abdominal computed tomography to determine the extent of tumor. Prognosis depends on tumor stage but is usually negative, 5-year survival rate is 5-10%.
Pathogenesis
Many experimental studies have demonstrated the intervention of numerous risk factors that may act in gastric cancer pathology. Food is one of the most important environmental factors incriminated. Consumption of food preserved by drying and smoke, excessive salt, turning nitrates into nitrites by the formation of N-nitroso compounds and nitrosamines-nitrosamide, decreased daily intake of dietary fiber, low intake of selenium is the true source of carcinogenic agents. Pathogenesis of Helicobacter pylori intervention in gastric cancer remains controversial. Following H. pylori infection has been a proliferation of gastric epithelial cells exaggerated chronic atrophic gastritis with installation vulnerability and increase epithelial cells from mutagens.
Diseases of the recommended daily risk of gastric cancer are chronic atrophic gastritis with intestinal metaplasia, Biermer anemia, gastric ulcers, stomach surgery for gastric or duodenal ulcer, gastritis and gastric polyps Menetrier. In gastric precancerous lesions with higher dysplasia is very important, representing a mandatory step in carcinogenesis.
The pathogenesis of gastric cancer have been proposed two hypotheses. Correa model is the most important current concept of pathogenesis of intestinal-type gastric cancer, starting from the atrophic gastritis with hypochlorhydria and aclorhidrie. The pathogenesis is multifactorial, stressing the role excess salt with the existence of inherited predisposing factors, the deficit in some micronutrients, vitamins and antioxidants. But Correa model explains less diffuse cancer. Tahara issued hypothesis specifies multiple mechanisms are involved in the pathogenesis of diffuse and intestinal type gastric cancer. It is believed that C-met gene that encodes protein C-Met, a receptor for liver cell growth factor is a key factor.
Dissemination is by contiguity, lymphatic, and peritoneal marrow.