Stomach cancer occurs when malignant cells develop in the inner lining of the stomach. It is also known as gastric cancer and grows slowly over a period of time. Diagnosing this disease is quite difficult. The initial symptoms include a sensation of feeling full even after eating a small quantity of food, feeling bloated, difficulty swallowing or dysphagia, severe persistent heartburn, indigestion, burping, and vomiting. The National Cancer Institute (NCI) states that every year, 1.7 percent of all cancer cases in the country are stomach cancer, and it is the third leading cause of death due to cancer.

Types of stomach cancer

• Adenocarcinoma
  Most stomach cancer patients (about 90% -95%) have adenocarcinomas. In this case, malignant cells develop in the innermost lining of the stomach.

• Lymphoma
  It occurs in the lymphatic system, and since lymph tissues are present on the wall of the stomach, Non-Hodgkin Lymphoma may develop in this organ. It is a rare type of gastric cancer and occurs in only 4 percent of cases.

• Gastrointestinal stromal tumor (GIST)
  It develops in the interstitial cells of the Cajal on the inner lining of the stomach. It is also a rare form of gastric cancer and may occur in any organ of the digestive tract. However, in 60 to 70 percent of cases, it appears in the stomach.

• Carcinoid tumors
  It develops in the hormone-making cells of the stomach, and usually, it does not spread to other organs. This type is found in about 3 percent of stomach cancer patients.

Causes of stomach cancer
The exact cause of stomach cancer is still unknown. However, the most common theory suggests that a mutation in the DNA of the cells makes them divide abnormally and at a very rapid pace. It leads to the accumulation of malignant cells on the stomach wall which forms a tumor.

Factors that may lead to stomach cancer

• Helicobacter pylori Infection and gastroesophageal reflux disease
  H. pylori infection is a common factor associated with stomach cancer . It is a harmful bacteria which may thrive in the mucous of the lining of the stomach. Out of every 3 stomach cancer patients, 1 has a history of H. pylori infection. In many cases, gastroesophageal junction cancer develops when the patient has a history of gastroesophageal reflux disease (GERD).

• Smoking
  Smoking also increases the chances of developing stomach cancer. The number of cigarettes smoked in a day is directly proportional to the incidence of gastric cancer. Studies reveal 1 out of 5 stomach cancer patients have a history of smoking.

In addition to the above factors, excessive consumption of smoked or salted food, eating less fresh fruits and vegetables, obesity, and a family history of cancer also increases the chances of stomach cancer.