Gastric cancer is a disease in which malignant cells form in the lining of the stomach.
The stomach is a J-shaped organ in the upper abdomen. It is part of the digestive system, which processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) in foods that are eaten and helps pass waste material out of the body. Food moves from the throat to the stomach through a hollow, muscular tube called the oesophagus. After leaving the stomach, partly-digested food passes into the small intestine and then into the large intestine (the colon).

The wall of the stomach is made up of 3 layers of tissue: the mucosal (innermost) layer, the muscularis (middle) layer, and the serosal (outermost) layer. Gastric cancer begins in the cells lining the mucosal layer and spreads through the outer layers as it grows.

Stromal tumours of the stomach begin in supporting connective tissue and are treated differently from gastric cancer.

Age, diet, and stomach disease can affect the risk of developing gastric cancer.
Risk factors include the following:
 

• Helicobacter pylori infection of the stomach.
   
• Chronic gastritis (inflammation of the stomach).
   
• Older age.
   
• Being male.
   
• A diet high in salted, smoked, or poorly preserved foods and low in fruits and vegetables.
   
• Pernicious anaemia.
   
• Smoking cigarettes.
   
• Intestinal metaplasia.
   
• Familial adenomatous polyposis (FAP) or gastric polyps.
   
• A mother, father, sister, or brother who has had stomach cancer.

Possible signs of gastric cancer include indigestion and stomach discomfort or pain.
These and other symptoms may be caused by gastric cancer or by other conditions.

In the early stages of gastric cancer, the following symptoms may occur:

Indigestion and stomach discomfort.
A bloated feeling after eating.
Mild nausea.
Loss of appetite.
Heartburn.
 

In more advanced stages of gastric cancer, the following symptoms may occur:

Blood in the stool.
Vomiting.
Weight loss (unexplained).
Stomach pain.
Jaundice (yellowing of eyes and skin).
Ascites (build-up of fluid in the abdomen).
Difficulty swallowing.
A doctor should be consulted if any of these problems occur.

Tests that examine the stomach and oesophagus are used to detect (find) and diagnose gastric cancer. The following tests and procedures may be used:
Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.

Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it.

Complete blood count: A procedure in which a sample of blood is drawn and checked for the following:
The number of red blood cells, white blood cells, and platelets.
The amount of haemoglobin (the protein that carries oxygen) in the red blood cells. The portion of the sample made up of red blood cells.
 

Upper endoscopy: A procedure to look inside the oesophagus, stomach, and duodenum (first part of the small intestine) to check for abnormal areas. An endoscope (a thin, lighted tube) is passed through the mouth and down the throat into the oesophagus.

Faecal occult blood test: A test to check stool (solid waste) for blood that can only be seen with a microscope. Small samples of stool are placed on special cards and returned to the doctor or laboratory for testing.

Barium swallow: A series of x-rays of the oesophagus and stomach. The patient drinks a liquid that contains barium (a silver-white metallic compound). The liquid coats the oesophagus and stomach and x-rays are taken. This procedure is also called an upper GI series.

Biopsy: The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. A biopsy of the stomach is usually done during the endoscopy.

CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

Certain factors affect treatment options and prognosis (chance of recovery). The treatment options and prognosis (chance of recovery) depend on the stage and extent of the cancer (whether it is in the stomach only or has spread to lymph nodes or other places in the body) and the patient’s general health.

After gastric cancer has been diagnosed, tests are done to find out if cancer cells have spread within the stomach or to other parts of the body. The process used to find out if cancer has spread within the stomach or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan the best treatment.

The following tests and procedures may be used in the staging process:

ßHCG (beta human chorionic gonadotropin), CA-125, and CEA (carcinoembryonic antigen) assays: Tests that measure the levels of ßHCG, CA-125, and CEA in the blood. These substances are released into the bloodstream from both cancer cells and normal cells. When found in higher than normal amounts, they can be a sign of gastric cancer or other conditions.

Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.

Endoscopic ultrasound (EUS): A procedure in which an endoscope (a thin, lighted tube) is inserted into the body. The endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography.

CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.

Laparoscopy: A surgical procedure to look at the organs inside the abdomen to check for abnormal areas. An incision (cut) is made in the abdominal wall and a laparoscope (a thin, lighted tube) is inserted into the abdomen. Tissue samples and lymph nodes may be removed for biopsy.

PET scan (positron emission tomography scan): A procedure to find malignant tumour cells in the body. A small amount of radionuclide glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumour cells show up brighter in the picture because they are more active and take up more glucose than normal cells.

The following stages are used for gastric cancer:

Stage 0 (Carcinoma in Situ)
In stage 0, cancer is found only in the inside lining of the mucosal (innermost) layer of the stomach wall. Stage 0 is also called carcinoma in situ.

Stage I
Stage I gastric cancer is divided into stage IA and stage IB, depending on where the cancer has spread.
Stage IA: Cancer has spread completely through the mucosal (innermost) layer of the stomach wall.
Stage IB: Cancer has spread: completely through the mucosal (innermost) layer of the stomach wall and is found in up to 6 lymph nodes near the tumour; or to the muscularis (middle) layer of the stomach wall.

Stage II
In stage II gastric cancer, cancer has spread: completely through the mucosal (innermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumour; or to the muscularis (middle) layer of the stomach wall and is found in up to 6 lymph nodes near the tumour; or to the serosal (outermost) layer of the stomach wall but not to lymph nodes or other organs.

Stage III
Stage III gastric cancer is divided into stage IIIA and stage IIIB depending on where the cancer has spread.
Stage IIIA: Cancer has spread to:
the muscularis (middle) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumour; or the serosal (outermost) layer of the stomach wall and is found in 1 to 6 lymph nodes near the tumour; or organs next to the stomach but not to lymph nodes or other parts of the body.
Stage IIIB: Cancer has spread to the serosal (outermost) layer of the stomach wall and is found in 7 to 15 lymph nodes near the tumour.

Stage IV
In stage IV, cancer has spread to: organs next to the stomach and to at least one lymph node; or more than 15 lymph nodes; or other parts of the body.

There are different types of treatment for patients with gastric cancer.

Different types of treatments are available for patients with gastric cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the "standard" treatment, the new treatment may become the standard treatment.

Four types of standard treatment are used:

Surgery

Surgery is a common treatment of all stages of gastric cancer. The following types of surgery may be used:

• Subtotal gastrectomy: Removal of the part of the stomach that contains cancer, nearby lymph nodes, and parts of other tissues and organs near the tumour. The spleen may be removed. The spleen is an organ in the upper abdomen that filters the blood and removes old blood cells.
• Total gastrectomy: Removal of the entire stomach, nearby lymph nodes, and parts of the oesophagus, small intestine, and other tissues near the tumour. The spleen may be removed. The oesophagus is connected to the small intestine so the patient can continue to eat and swallow.

If the tumour is blocking the opening to the stomach but the cancer cannot be completely removed by standard surgery, the following procedures may be used:

• Endoluminal stent placement: A procedure to insert a stent (a thin, expandable tube) in order to keep a passage (such as arteries or the oesophagus) open. For tumours blocking the opening to the stomach, surgery may be done to place a stent from the oesophagus to the stomach to allow the patient to eat normally.
• Endoscopic laser surgery: A procedure in which an endoscope (a thin, lighted tube) with a laser attached is inserted into the body. A laser is an intense beam of light that can be used as a knife.
• Electrocautery: A procedure that uses an electrical current to create heat. This is sometimes used to remove lesions or control bleeding.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly in the spinal column, a body cavity such as the abdomen, or an organ, the drugs mainly affect cancer cells in those areas. The way the chemotherapy is given depends on the type and stage of the cancer being treated.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemoradiation

Chemoradiation combines chemotherapy and radiation therapy to increase the effects of both. Chemoradiation treatment given after surgery to increase the chances of a cure is called adjuvant therapy. If it is given before surgery, it is called neoadjuvant therapy.

Other types of treatment are being tested in clinical trials. These include the following:

Biologic therapy

Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defences against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.

Treatment Options by Stage
Stage 0 Gastric Cancer (Carcinoma in Situ)
Treatment of stage 0 gastric cancer may include the following:

Surgery (total or subtotal gastrectomy).
Stage I and Stage II Gastric Cancer
Treatment of stage I and stage II gastric cancer may include the following:

Surgery (total or subtotal gastrectomy).
Surgery (total or subtotal gastrectomy) followed by chemoradiation therapy.
A clinical trial of chemoradiation therapy given before surgery.

Stage III Gastric Cancer
Treatment of stage III gastric cancer may include the following:

Surgery (total gastrectomy).
Surgery followed by chemoradiation therapy.
A clinical trial of chemoradiation therapy given before surgery.

Stage IV Gastric Cancer
Treatment of stage IV gastric cancer that has not spread to distant organs may include the following:

Surgery (total gastrectomy) followed by chemoradiation therapy.
A clinical trial of chemoradiation therapy given before surgery.
Treatment of stage IV gastric cancer that has spread to distant organs may include the following:

Chemotherapy as palliative therapy to relieve symptoms and improve the quality of life.
Endoscopic laser surgery or endoluminal stent placement as palliative therapy to relieve symptoms and improve the quality of life.
Radiation therapy as palliative therapy to stop bleeding, relieve pain, or shrink a tumour that is blocking the opening to the stomach.
Surgery as palliative therapy to stop bleeding or shrink a tumour that is blocking the opening to the stomach.

Treatment Options for Recurrent Gastric Cancer
Treatment of recurrent gastric cancer may include the following:

Chemotherapy as palliative therapy to relieve symptoms and improve the quality of life.
Endoscopic laser surgery or electrocautery as palliative therapy to relieve symptoms and improve the quality of life.
Radiation therapy as palliative therapy to stop bleeding, relieve pain, or shrink a tumour that is blocking the stomach.
A clinical trial of new anticancer drugs or biologic therapy.
 

BACK