1. What is the function of the stomach?
The stomach is an organ in a "J" at the top of the abdomen. It is part of the digestive system, whose responsibility is to process the food eaten by extracting them nutrients (vitamins, minerals, carbohydrates, fats, proteins and water). The food is conducted from the throat to the stomach, through a hollow, muscular tube called the esophagus. After leaving the stomach, food passes partially digested in the small intestine and then to the large intestine (colon).
The stomach wall consists of three layers of tissue: the mucosa layer (layer which is in contact with food), the muscular layer (middle layer), and the serosa layer (outside the lining of the stomach).
2. What is Stomach Cancer?
The Cancer Stomach (or Gastric Cancer) is the growth of abnormal cells in the organ of this digestive system and can occur anywhere in its length. Much of this type of tumor occurs in the mucous layer (inner coating layer), appearing in the form of small lesions with irregular ulcerations (disruption of the mucosal tissue) - characteristics of cancers or malignant tumors.
As the evolution of cancer, these abnormal cells are gradually replacing the normal tissue of the body, spreading to other layers of the stomach and can affect nearby organs (metastasis by contiguity).
Stomach cancer is the second most common malignancy in the world, with high incidence in Eastern Europe, Japan, South America (mainly Chile and Colombia) and Central America (Costa Rica). According to data INCA (National Cancer Institute), 21,500 new cases are still diagnosed this year, and 13,820 men and 7,680 women.
Excluding skin cancers, adenocarcinoma of the stomach in men is the second most common cancer in the North (11 / 100,000) and Northeast (9 / 100,000) and third in the South (24 / 100,000), Southeast (21 /100.000) and Midwest (13 / 100,000). For women is the third most common in the North (6 / 100,000), the fourth in the Northeast (5 / 100,000) and the fifth in the Midwest (6 / 100,000), Southeast (11 / 100,000) and South (12 /100.000) (INCA, 2004). It is the second leading cause of cancer death among men in São Paulo (FONSECA, LAM, 1996).
In Pius XII Foundation - Barretos Cancer Hospital, in 2009, gastric adenocarcinoma was the fourth most common cancer, with 414 new cases, preceded by prostate cancer (1008 cases), breast (866 cases) and lung (405 cases).
With the peak incidence in older men (about 65% of diagnosed patients are older than 50 years), stomach cancer ranks third in incidence between men and fifth among women.
3. Types of Stomach Cancer
The stomach cancer usually begins in cells of the mucous layer (inner layer in contact with food) and spreads through the outer layers as it grows.
Stomach tumors present predominantly in the form some histological types: adenocarcinoma (responsible for 95% of tumors), lymphoma (diagnosed in about 3% of cases) and leiomyosarcoma (started in tissues that give rise to the muscles and bones).
Adenocarcinoma
Adenocarcinoma is a type of cancer (malignancy) that has secretory characteristics, originating in glandular tissue. It is the third most common malignant tumor in the world after lung and breast cancer - according to data from the National Cancer Institute. Its incidence has declined in Western countries, but still remains a leading cause of death worldwide.
Japanese Recent statistics show that gastric cancer in Japan is responsible for the second cause of death among men and chief among women. However, in the last two decades, the death rate due to gastric cancer has declined in Japan and some Western countries, due to earlier diagnosis, more aggressive surgical technique, the most effective chemotherapy drugs and patient care (NAKAJIMA T; 2005).
Lymphoma
Lymphoma is a type of cancer that originates in the nodes (ganglia) throughout the body, particularly in the thymus, spleen, tonsils, bone marrow and lymphatic tissues in the intestines. Like other types of lymphomas, they are divided into subtypes complex between Hodgdkin lymphoma and non-Hodgkin lymphoma.
Hodgkin's stomach has a low incidence (3% of stomach cancers) can be divided into two types:
Gastric MALT lymphoma (Musoca-associated lymphoid tissue) - is a type of lymphoma associated with mucosa made up of small cells with low-grade malignancies.
The second type is a lymphoma large and highly malignant cells, but with a very rare incidence (when compared with gastric MALT lymphoma).
Leiomyosarcoma
The leiomyosarcoma is a benign tumor of the smooth muscle of the stomach, usually located in any organ as well. Its incidence is low.