Stomach Cancer: Symptoms, Causes, And Prevention
What is Stomach Cancer?
Stomach Cancer (a.k.a: Gastric Cancer) develops when the cells of the stomach divide abnormally. The abnormal growth of cells causes accumulation of the cells leading to the formation of a tumor. In 90 – 95 % of the cases, cancer starts from the cells of the inner lining of the stomach. In remaining cases, cancer starts from the cells of the stomach body or the gastroesophageal junction (the point where the food pipe or the oesophagus meets the stomach).
According to the World Health Organisation (WHO), stomach cancer is the fifth most common cancer in the world, and it is the third leading cause of cancer-related death cases. Approximately, 723000 deaths are caused by stomach cancer every year worldwide. In India, less than 1 million cases of stomach cancer are reported every year.
What are the Symptoms of Stomach Cancer?
The stomach cancer causes symptoms which are similar to less serious gastric conditions. This makes the diagnosis of stomach cancer a little difficult in the initial stage. The various symptoms in the initial stage include:
- Severe heartburn
- Severe stomach pain
- Bloating after eating
- Persistent indigestion
- Feeling full after consuming a small quantity
Symptoms during the advanced stage of cancer include:
- Weight loss
- Appetite loss
- Blood in stools
What are the Causes of Stomach Cancer?
Stomach cancer is caused when a mutation in the stomach cells causes the cells to divide abnormally. The abnormal growth of cells results in the formation of a tumour. The cancerous cells survive, and the normal cells die. Few cells from the tumor break off and spread to the other parts of the body.
Which Factors Increases the Risk of Stomach Cancer?
Studies have shown the various factors which increase the risk of developing stomach cancer. These factors are discussed below:
- Age: Individuals who are more than 55 years of age are more likely to develop stomach cancer.
- Gender: The risk of developing stomach cancer is twice in men when compared to women.
- Ethnicity: Asian, Hispanic and Black individuals have high possibility of experiencing stomach cancer when compared to white individuals.
- Obesity: Being obese increases the risk of stomach cancer in men. There is no sufficient data regarding obesity’s link to stomach cancer in women.
- Alcohol Abuse: Over consumption of alcohol increases the probability of developing stomach cancer.
- Smoking: Individuals who smoke are at high risk of developing stomach cancer as the tobacco contains a harmful chemical that damage the lining of the stomach.
- Helicobacter Pylori Infection: Helicobacter pylori infection causes stomach inflammation and ulcers. Thus, it increases the risk of developing stomach cancer.
- Diet: Individuals who consume fewer fruits and vegetables and high amounts of salty, pickled and smoked food are at high risk of experiencing stomach cancer.
- Family History: Individuals whose close family members have stomach cancer has high probability of developing cancer.
- Other Cancer: Individuals who have other cancers are at high risk of experiencing stomach cancer.
How is Stomach Cancer Diagnosed?
Diagnosis of stomach cancer in the initial stage is difficult as the symptoms of stomach cancer are similar to the other diseases. In most of the cases, diagnosis is done in the advanced stage. The following diagnostic tests are done:
- Upper Gastrointestinal Endoscopy: The stomach of the individual is examined by using an endoscope. The endoscope is a thin tube which has a camera at the end. The individual is sedated, and the endoscope is inserted down the throat into the stomach.
- Endoscopic Ultrasound: In endoscopic ultrasound, an ultrasound probe is attached to the endoscope. The ultrasound probe uses ultrasound waves to form an image of the stomach.
- Biopsy: During the endoscopy, if a suspicious tissue is identified a biopsy is done. In the biopsy, the tissue is extracted and sent to the laboratory for further studying.
- Laparoscopy: Laparoscopy is done to determine if cancer has spread to the abdominal cavity. This cannot be identified by imaging techniques. In laparoscopy, a laparoscope (a thin flexible tube with an optic light and camera at one end) is inserted into the abdominal cavity to take pictures of the abdominal cavity.
- Imaging Tests: Imaging test done for the diagnosis of stomach cancer include,
- X-Ray: X-ray technique use beams of x-rays to form an image of the stomach.
- Barium Swallow X-Ray: In barium swallow technique, the individual is administered a solution of barium orally, and then an x-ray is taken. The barium solution lines the oesophagus, intestines and the stomach. If tumor is present, it is easily seen.
- Computed Tomography (CT) Scan: Computerised tomography scan forms a 3-dimensional image of the stomach by taking x-rays from the different directions. It is useful in determining the size of the tumor.
- Magnetic Resonance Imaging (MRI Scan): In magnetic resonance imaging technique, a strong magnetic field and radio waves are used to form a detailed image of the stomach. It determines the stage of stomach cancer.
- Positron Emission Tomography (PET) Scan: Positron emission tomography scan is done by injecting a radioactive sugar to the patient. This sugar is taken up by the most active cells, cancer cells being the most active takes this sugar. The scanner detects this and forms an image.
How is Stomach Cancer Treated?
The stomach cancer treatment depends on the extent to which cancer has spread and the choice of the individual. The various treatment options include the following:
Surgery: The various surgeries done include:
- Endoscopic Mucosal Resection: Tiny tumors present in the lining of the stomach are removed in the endoscopic mucosal resection.
- Subtotal Gastrectomy: In subtotal gastrectomy, only the affected part of the stomach is removed.
- Total Gastrectomy: Total gastrectomy involves removing the entire stomach and its surrounding tissues.
- Lymphadenectomy: The lymph nodes in the stomach are removed as there is a high possibility of them being affected.
Chemotherapy: In chemotherapy, the growth of cancerous cells is inhibited by oral or intravenous administration of drugs.
Radiation Therapy: High energy x-rays are used for killing the cancer cells in the radiation therapy. It is used before the surgery to shrink the tumor or after the surgery to kill the remaining cancer cells.
Targeted Drug Therapy: In targeted drug therapy, certain modifications are done within the cancer cells, or the immune system inhibits the growth of the cancer cells. Ramucirumab and trastuzumab are the two drugs approved for targeted drug therapy.
How is Stomach Cancer Prevented?
It is not possible to prevent stomach cancer as it is unknown what triggers mutation which leads to cancerous growth. The following preventive measures can be taken to reduce the risk of developing stomach cancer:
- Stay Healthy: Physical activity must be done every day as daily exercise reduces the weight thereby, reducing the risk of developing stomach cancer.
- Eat Wisely: The individuals are recommended to include a sufficient amount of fruits and vegetables in the diet. It is recommended to avoid pickled, salty and smoked food.
- Stop Smoking: Smoking doubles the risk of developing cancers. So the individuals should stop smoking.
- Avoid Alcohol: Individuals are recommended not to consume alcohol in large quantities as it increases the risk of stomach cancer.