What is gastric cancer?
There are different kinds of cancer that afflict the stomach. The most common kind is called adenocarcinoma. This cancer begins in cells that form the lining of the stomach. It presents itself in two forms: intestinal type, more common among men and appearing at younger ages; diffuse type, more common among women and individuals older than 50. The presence of the bacteria H. Pylori in the stomach is highly associated with this kind of cancer.
What are the risk factors associated with gastric cancer?
Environmental factors are related with gastric cancer, such as lack of hygiene and deficient nutrition, as well as mishandling of food and water. Diets high in fruits, vegetables with leves, ascorbic acid, and betacarotene are associated with a low risk. While there has not been an association demonstrated with smoking, it can nonetheless increase the risk of pre-malignant lesions.
The most important significant risk factor associated with gastric cancer is the presence of the bacteria Helicobacter Pylori the stomach, increasing the odds by eight-fold.
What are the symptoms?
The first stages of gastric cancer typically present no symptoms. Late stage symptoms commonly include weight loss, abdominal pain, sensation of fullness in the upper abdomen, nausea, loss of appetite, and mild stomach discomfort. Gastric hemorrhage is infrequent, occurring in around 20% of the cases.
How is it diagnosed?
Approximately 65% of patients with gastric cancer are diagnosed with disease in advanced stage or with metastasis. A physical examination can provide clues for the diagnosis. The presence of anemia, occult blood in feces, and weight loss can be suggestive of a tumor. Findings in the physical examination can include a mass in the abdomen, bloating, weight loss, and weakness. An endoscopy is the most effective method for the diagnosis of gastric cancer.
What is an endoscopy?
This procedure allows for direct visualization of the stomach. This is accomplished with the use a flexible scope that is introduced into the stomach through the mouth which transmits images in real time to a monitor for observation by a physician. Biopsies or tissue samples can be obtained for analysis under the microscope in order to obtain a precise diagnosis. More than 90% of gastric cancer cases are detected by endoscopic examination.
Ulcerated Gastric Cancer
Polyp-type Gastric Cancer
How is gastric cancer treated?
Currently there are three approaches to the treatment of gastric cancer, depending on how advanced the disease is. Curative resections are effective during early stages of the disease; these can be achieved endoscopically. Surgical resection is comprised of the resection of the primary tumor and surrounding lymph nodes. Chemotherapy is also available, but has shown limited success.
With current endoscopic technology such as chromoendoscopy and magnification it is possible to detect subtle, microscopic cellular changes in the stomach tissue that are considered pre-malignant and are at risk of developing into tumor tissue.
Cromoendoscopia Electrónica (C. E.)
C. E. y Magnificación
When an early diagnosis is achieved, it is possible to undergo minimally invasive surgery through endoscopy and achieve complete resection of the pre-malignant lesions, therefore eliminating the possibility of an advanced stage cancer.
This procedure is called Endoscopic Submucosal Dissection (ESD). It is an advanced method of minimally invasive surgery used to eliminate or resect pre-malignant lesions from the digestive system. These lesions include metaplasia, and low- or high-grade dysplasia. High-grade dysplasia is considered an initial stage of cancer (in Situ)
The resulting prognosis following the ESD depends on the initial state of the lesions. Early tumors confined to the lining of the stomach have high cure rates in comparison to cases where disease has spread to distant sites or neighboring lymph nodes. The cure rates of early lesions have improved over the last three decades, especially in Japan. This improvement can be attributed to the increase in the detection of early lesions.
Currently there are two main kinds of gastric resection: subtotal gastrectomy and total gastrectomy. Determining the kind of resection ton undergo depends on a number of factors including: 1) location of the tumor, 2) size and extension, and 3) histological pattern.
Curative surgical resections generally include lypmhadenectomy, or the surgical removal or regional lymph nodes.
A gastrojejunostomy is typically done after the gastrectomy is performed.
Patients with more advanced lesions may require palliative therapy (not curative). By means of endoscopy it is possible to perform resection or ablation of the tissue, dilation of stenosis, stent placement, bleeding control, and placement of feeding tubes.
Metallic stent opening the obstruction caused by a gastric tumor.