Stomach cancer

Other Names: Adult stomach cancer; Adult stomach carcinoma; Stomach carcinoma; Gastric cancer

Stomach cancer, also called gastric cancer, is a form of cancer that occurs due to abnormal and uncontrolled cell growth in the stomach.

Endoscopic image of linitis plastica, a type of stomach cancer where the entire stomach is invaded, leading to a leather bottle-like appearance with blood coming out of it

Cause

Although the underlying cause of some familial cases is unknown, genetic changes (mutations) are identified in a subset of people affected by stomach cancer.

Risk factors

Age, diet, and stomach disease can affect the risk of developing gastric cancer. Having any of the following medical conditions:

• Helicobacter pylori (H. pylori) infection of the stomach.
• Chronic gastritis (inflammation of the stomach).
• Pernicious anemia.
• Intestinal metaplasia (a condition in which the normal stomach lining is replaced with the cells that line the intestines).
• Gastric polyps.
• Epstein-Barr virus.
• Familial syndromes (including familial adenomatous polyposis).
• Eating a diet high in salted, smoked foods and low in fruits and vegetables.
• Eating foods that have not been prepared or stored properly.
• Being older or male.
• Smoking cigarettes.
• Having a mother, father, sister, or brother who has had stomach cancer.

Signs and symptoms

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 signs and symptoms may occur:

• Blood in the stool.
• Vomiting.
• Weight loss for no known reason.
• Stomach pain.
• Jaundice (yellowing of eyes and skin).
• Ascites (build-up of fluid in the abdomen).
• Trouble swallowing.

Diagnosis

Endoscopic images of the stomach cancer in early stage. Its histology was poorly differentiated adenocarcinoma with signet ring cells. Left above: normal, right above: FICE, left low: acetate stained, right low: AIM stained

The following tests and procedures may be used: Physical exam and health 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.

Complete blood count (CBC): 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 hemoglobin (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 esophagus, 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 esophagus.

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

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.

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. The sample of tissue may be checked to measure how many HER2 genes there are and how much HER2 protein is being made. If there are more HER2 genes or higher levels of HER2 protein than normal, the cancer is called HER2 positive. HER2-positive gastric cancer may be treated with a monoclonal antibody that targets the HER2 protein.

The sample of tissue may also be checked for Helicobacter pylori (H. pylori) infection.

Treatment

Seven types of standard treatment are used:

• Surgery
• Endoscopic mucosal resection
• Chemotherapy
• Radiation therapy
• Chemoradiation
• Targeted therapy
• Immunotherapy

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 tumor. The spleen may be removed. The spleen is an organ that makes lymphocytes, stores red blood cells and lymphocytes, filters the blood, and destroys old blood cells. The spleen is on the left side of the abdomen near the stomach.

Total gastrectomy: Removal of the entire stomach, nearby lymph nodes, and parts of the esophagus, small intestine, and other tissues near the tumor. The spleen may be removed. The esophagus is connected to the small intestine so the patient can continue to eat and swallow. If the tumor is blocking 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 esophagus) open. For tumors blocking the passage into or out of the stomach, surgery may be done to place a stent from the esophagus to the stomach or from the stomach to the small intestine to allow the patient to eat normally.

Endoluminal laser therapy: 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.

Gastrojejunostomy: Surgery to remove the part of the stomach with cancer that is blocking the opening into the small intestine. The stomach is connected to the jejunum (a part of the small intestine) to allow food and medicine to pass from the stomach into the small intestine.

Endoscopic mucosal resection Endoscopic mucosal resection is a procedure that uses an endoscope to remove early-stage cancer and precancerous growths from the lining of the digestive tract without surgery. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also include tools to remove growths from the lining of the digestive tract.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them 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 into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.

A type of regional chemotherapy being studied to treat gastric cancer is intraperitoneal (IP) chemotherapy. In IP chemotherapy, the anticancer drugs are carried directly into the peritoneal cavity (the space that contains the abdominal organs) through a thin tube.

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment used during surgery that is being studied for gastric cancer. After the surgeon has removed as much tumor tissue as possible, warmed chemotherapy is sent directly into the peritoneal cavity.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. External radiation therapy uses a machine outside the body to send radiation toward the area of the body with cancer.

Chemoradiation

Chemoradiation therapy combines chemotherapy and radiation therapy to increase the effects of both. Chemoradiation given after surgery, to lower the risk that the cancer will come back, is called adjuvant therapy. Chemoradiation given before surgery, to shrink the tumor (neoadjuvant therapy), is being studied.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do. Monoclonal antibodies and multikinase inhibitors are types of targeted therapy used in the treatment of gastric cancer.

Monoclonal antibody therapy: This type of therapy uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells. There are different types of monoclonal antibody drugs:

Trastuzumab blocks the effect of the growth factor protein HER2, which sends growth signals to gastric cancer cells. Ramucirumab blocks the effect of certain proteins, including vascular endothelial growth factor. This may help keep cancer cells from growing and may kill them. It may also prevent the growth of new blood vessels that tumors need to grow. Trastuzumab and ramucirumab are used in the treatment of stage IV gastric cancer and gastric cancer that cannot be removed by surgery or has recurred.

Multikinase inhibitors: These are small-molecule drugs that go through the cell membrane and work inside cancer cells to block multiple protein signals that cancer cells need to grow and divide. Some multikinase inhibitors also have angiogenesis inhibitor effects. Angiogenesis inhibitors stop the growth of new blood vessels that tumors need to grow. There are different types of multikinase inhibitor drugs:

Regorafenib is a multikinase inhibitor and angiogenesis inhibitor that blocks the effects of the multiple proteins inside tumor cells. Regorafenib is being studied in the treatment of stage IV gastric cancer and gastric cancer that cannot be removed by surgery or has recurred. See Drugs Approved for Stomach (Gastric) Cancer for more information.

Immunotherapy

Immunotherapy 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 defenses against cancer. This type of cancer treatment is also called biotherapy or biologic therapy.

Immune checkpoint inhibitor therapy is a type of immunotherapy.

Immune checkpoint inhibitor therapy: PD-1 is a protein on the surface of T cells that helps keep the body’s immune responses in check. When PD-1 attaches to another protein called PDL-1 on a cancer cell, it stops the T cell from killing the cancer cell. PD-1 inhibitors attach to PDL-1 and allow the T cells to kill cancer cells. Pembrolizumab is a type of immune checkpoint inhibitor.

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition.

• ramucirumab (Brand name: Cyramza) Treatment of advanced gastric or gastro-esophageal junction adenocarcinoma, as a single agent or in combination with paclitaxel, after prior fluoropyrimidine- or platinium-containing chemotherapy.

Prognosis

When gastric cancer is found very early, there is a better chance of recovery. Gastric cancer is often in an advanced stage when it is diagnosed. At later stages, gastric cancer can be treated but rarely can be cured.

NIH genetic and rare disease info

• NIH info on Stomach cancer

Stomach cancer is a rare disease.

Stomach cancer Resources
Latest articles Most recent articles Ongoing trials	Wikipedia