Stomach Cancer
The stomach is an organ shaped like a wineskin located in the upper abdomen and connects the esophagus to the first portion of the intestine (duodenum). Its main function is to accumulate ingested food and begin digestion. Other functions are to provide absorption of iron and vitamin B12.
Stomach cancer occurs because the cells of the inner layer (mucosa) multiply out of control. Initially this multiplication affects only the mucosa, forming a lump. He soon breaks the barrier that limits the mucosa and tumor cells are invading the different layers of the stomach wall.
Growing up the tumor may invade other organs and can spread in three ways: through the ducts to the lymph nodes (lymph node metastases), through the blood to other organs, especially the liver (distant metastasis) or through the peritoneum to all the abdomen (peritoneal carcinomatosis).
Stomach cancer, like all cancers, is due to an alteration of genes in the body’s own cells, which causes them to multiply uncontrollably, destroying or encroaching on what they find in their path in a process that usually takes months or years. These genes are altered primarily by the action of some substances called carcinogens.
The incidence (number of cases detected in a year in a given population) of stomach cancer has important variations between countries, being 20 times more frequent in Japan and Far Eastern countries than in countries less affected, as Senegal. Spain is located at an intermediate level. Anyway, surprisingly the reduction in incidence has been recorded in the last 40 years, especially in people older and white. The disease usually appears between 50 and 70 years and is very rare before age 30.