Stomach (gastric) cancer remains a major health concern in many countries. Each year, over one million cases of stomach cancer are diagnosed around the world. It is the seventh most prevalent, and fifth most diagnosed cancer in the world. Likewise, esophageal cancer is the ninth most common cancer and the sixth most common cause of cancer deaths worldwide. However, the incidence rates may vary according to region worldwide.
Typically, stomach and esophageal cancers are slow growing cancers, where the symptoms may not appear until the advanced stages. Stomach and esophageal cancers are more common in men compared to women. They can occur at any age but are more common in people aged over 60 years. Many factors may influence the development of cancer, which may include genetic, immunologic, infectious, and environmental factors.
A brief overview of stomach and esophageal cancer
The cancers that originate from the tissues of the stomach or esophagus are known as stomach or esophageal cancer. The esophagus and stomach are part of the upper gastrointestinal tract of the digestive system. Esophagus is a long, hollow tube that carries the food consumed, from the back of the throat to the stomach. Stomach is a muscular organ located on the left side of the upper abdomen. It holds food that enters from the esophagus and initiates the digestion process by secreting acids and enzymes. The partly digested food enters the first part of the small intestine known as duodenum.
Causes of stomach and esophageal cancer
The exact cause of stomach and esophageal cancers are unknown, but certain factors may increase the risk for developing such cancers. Listed are the factors that may influence the risk of developing stomach or esophageal cancer.
- Aged over 60
- Being male
- Helicobacter pylori (H. pylori) infection
- Chronic gastritis
- Alcohol consumption
- Pernicious anemia (lower levels of red blood cells)
- Family history for stomach or breast cancer
- Overweight or Obesity
- Aged over 60 years
- Overweight or obesity
- Inherited genetic conditions such as familial adenomatous polyposis (FAP), Lynch syndrome, gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) or hereditary diffuse gastric cancer (HDGC)
- Medical conditions such as gastro esophageal reflux disease, (GORD) and Barrett’s esophagus
- Inherited genetic condition such as PeutzJeghers syndrome (PJS) or Cowden syndrome Squamous cell carcinoma
- Drinking very hot liquids
- Alcohol consumption
Signs and symptoms
Stomach and esophageal cancers in their early stages may not cause symptoms. If the symptoms occur, they are common to many other conditions and as a result, the cancers are usually diagnosed at later stages. It is essential to seek medical advice if there is a concern or when the symptoms persist for a long time.
Stomach cancer may be associated with pain or burning sensation in the stomach. It may cause abdominal discomfort and indigestion with frequent burping. People with stomach cancer may also experience persistent bloating. When the cancer develops in the esophagus, it may lead to upper abdominal discomfort, especially while eating. It is also associated with difficult or painful swallowing, and hoarseness. People with esophageal cancer may also experience pain in the throat, behind the breastbone, or between the shoulder blades.
Other symptoms that are common for both the cancers include:
- Loss of appetite
- Unintentional weight loss
- Nausea and vomiting
- Blood in vomit
- Black or tarry stools
Several tests and procedures may be used in the diagnosis of stomach and esophageal cancers. The common tests may include:
Medical history and physical exam: The medical history includes information about the symptoms such as pain, bloating and difficulty while eating. Information related to the possible risk factors are also obtained. Physical examination may be performed to examine the abdomen for abnormalities and other information related to general health.
Barium swallow test: A barium study is performed to examine the upper part of the digestive system such as the esophagus, stomach, and duodenum. During this study, the patient is asked to swallow a fluid containing barium that coats the inside of the organs and reveal any abnormalities present in the tissue on the X-ray.
Endoscopy: During endoscopy, a long, flexible tube with a light and camera on the end (endoscope) is passed into the mouth, down to the throat through esophagus, and into the stomach. It helps to visualize and identify the areas of irritation or abnormalities.
Biopsy: If there are any suspicious findings during endoscopy, a special scope is used to collect a sample tissue for examination under a microscope.
Once the diagnosis of cancer is confirmed, further tests may be recommended to know if the cancer has spread to the other parts of the body. This process is known as cancer staging, which helps to determine the treatment and prognosis. Such tests may include:
Endoscopic ultrasound: During this test, an endoscope with an ultrasound probe on one end is inserted into the mouth, down to the throat through esophagus, and into the stomach. The sound waves produced by the ultrasound probe help to determine whether the cancer has spread into the esophageal wall, nearby tissues or lymph nodes.
Computed tomography (CT): CT uses x-ray beams to create detailed cross-sectional images of insides of the body. It is often used to evaluate the extent of the tumor spread to other parts of the body such as the chest, abdomen, and pelvis.
Positron emission tomography (PET): A PET scan uses a special dye containing radioactive tracers that mainly adheres to the cancer cells. A special camera is used to create a picture of areas of radioactivity in the body. Sometimes, PET scan is combined with a CT scan to provide more detailed and accurate information about the cancer.
Staging of stomach and esophageal cancer
Stages of stomach and esophageal cancers include:
Stage I: Tumors are confined to the stomach or esophageal wall lining.
Stages II–III: Tumors have spread deeper into the layers of the stomach or esophageal wall and to nearby lymph nodes.
Stage IV: Tumors have spread beyond the stomach or esophagus to distant lymph nodes and parts of the body.
Following are the treatment options for stomach and esophageal cancer depending on the location and extent of the cancer.
Endoscopic resection: Endoscopic resection could be a treatment option for small early-stage tumors. They can be removed using a long, flexible tube (endoscopic resection) inserted through the throat to reach the tumor site. In some cases, it may be the only treatment required to cure a stomach or esophageal cancer.
Surgery: Surgery is a common choice of treatment used to cure stomach and esophageal cancer. It aims to remove all the cancer while leaving as much normal tissue as possible. Some of the healthy tissue around the cancer may be removed to reduce the risk of the cancer recurrence.
Surgical procedures for stomach cancers include:
Gastrectomy: It involves removal of a part or all the stomach, leaving as much healthy tissue as possible.
- Subtotal or partial gastrectomy: When a part of the stomach is removed along with nearby fatty tissue and lymph nodes, it is referred as subtotal or partial gastrectomy.
- Total gastrectomy: When the entire stomach is removed, along with the nearby fatty tissue, lymph nodes and parts of nearby organs, it is referred as total gastrectomy.
Surgical procedures for esophageal cancers include:
Esophagectomy: It involves removal of the tumor and part or the entire esophagus along with the affected lymph nodes, leaving as much healthy tissue as possible.
Radiation therapy: Radiation therapy involves the use of controlled dose of radiation (X-rays and protons) to destroy the cancerous cells. It can be given alone or combined with chemotherapy (chemoradiation) for people with stomach or esophageal cancer. It can be used as a main treatment for cancers that have not spread to other parts of the body, or when surgery is not an option. It is used before the surgery to shrink large tumors and destroy any cancer cells that may have spread. Occasionally, the surgery may help minimize the chances for cancer recurrence, and relieve complications associated with advanced cancers.
Chemotherapy: Chemotherapy involves the use of anti-cancer drugs to destroy or slow the growth of cancer cells. They are either given alone or combined with radiation therapy. Chemotherapy alone is used for people unable to undergo surgery. It is used before the surgery to shrink large tumors and destroy any cancer cells that may have spread. It may be used after the surgery to reduce the risk of cancer recurrence.
Targeted drug therapy: Targeted therapy is designed to attack specific features of the cancer cells, thereby causing the cancer cells to die or stop spreading. They can be used alone or in combination with chemotherapy for advanced cancers or cancers that do not respond to other treatments.
Immunotherapy: Immunotherapy is a drug treatment that boosts the immune system to fight cancer. Cancer cells remain protected from the immune system action as they produce proteins that interfere prevent the immune system from recognizing them as harmful. Immunotherapy works by interrupting with that process, and is commonly used in advanced stages, or when the cancer recurs.
Stomach and esophageal cancer cannot be prevented; however certain measures can help reduce the risk. They include:
- Quitting smoking
- Avoiding or limiting alcohol consumption
- Eating more fruits and vegetables
- Being physically active
- Maintaining healthy weight
Prognosis and survival in patients with stomach and esophageal cancer depends on the stage of the disease. The patient diagnosed with cancer at very early stage has better chances of survival. The 5-year survival rate for cancer that is confined to stomach is 70%. When the cancer spreads to the surrounding lymph nodes or organs, the 5-year survival rate is 30%. The 5-year survival rate for esophageal cancer that is present within the esophagus is 47% and 25% for those which have spread to surrounding organs or lymph nodes. When the cancer has spread to distant parts of the body, the five-year survival rate is 5%.
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