Stomach cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs, or gastric cancer, is a malignancy that develops in the lining of the stomach. The stomach is an organ in the upper abdomenstomach, stomach area, belly that stores and digests food.
The stomach has four tissuea group of cells that work together to perform a function layers: the mucosa, submucosa, muscle layer and outer layer. The mucosa is the inner-most layer that produces digestive juices (specifically hydrochloric acid and pepsin) to break down food, and mucus to protect the lining of the stomach. The second inner-most layer, the submucosa, supports the mucosa layer, and provides bloodthe red bodily fluid that transports oxygen and other nutrients around the body and nutrients to the stomach. It contains a variety of blood vessels, lymphatic vessels, and nerves. The next layer is the muscle layer, also known as the muscularis externa, which is responsible for producing contractions to further help break down food and push it to the small intestinea section of the gastrointestinal tract that recieves food from the stomach and absorbs the nutrients from food, also called small bowel. The outer-most layer is the serosa, which is a smooth, protective membrane that surrounds the stomach.
Stomach cancers are more common in males, and are generally found in people over 60 years old. However, anyone can develop this disease.
Types of Stomach Cancer
There are several types of stomach cancers, which can be categorised by the type of cellsthe basic structural and functional unit of all living things they develop from.
Gastric Adenocarcinomas
Gastric adenocarcinomas are the most common form of stomach cancer. Adenocarcinomas are cancers arising from mucus-producing glands in organs, and start in the mucosa of the stomach. Gastric adenocarcinomas can be aggressive, but can have a good prognosisto predict how a disease/condition may progress and what the outcome might be when caught early.
Linitis Plastica
Linitis plastica, also known as gastric scirrhous carcinomacancer arising from tissues that line organs, is a very rare form of stomach cancer that is classified as a form of gastric adenocarcinomacancer arising from mucus-producing glands in organs. It develops in the lining of the stomach and spreads to the muscles of the stomach wall, making it thick, hard and rubbery. Once this occurs, the stomach can’t hold as much food, and doesn’t move as much as it should during digestion. Linitis plastica is often aggressive, and may not have as good of a prognosis as other stomach cancers.
Gastric Lymphomas
Gastric lymphomas are stomach cancers that often develop from lymphocytes in the lining of the stomach. It is a type of non-Hodgkin lymphomacancers of the lymphatic system that affects the immune system. They are often slow-growing, and may carry a good prognosis.
Gastrointestinal Stromal Tumours (GISTs)
A gastrointestinal stromal tumoura tissue mass that forms from groups of unhealthy cells (GIST) is a rare type of sarcomacancer arising from bones and/or soft tissue that forms in lining of the gastrointestinal tract. More specifically, they develop in interstitial cells of Cajal (ICC), which play a critical role in the intestinal contractions required for digestion. For more information on GISTs, please refer to the Rare Cancers Australia Gastrointestinal Stromal Tumours (GIST) page.
Gastro-oesophageal Junction Cancer
Gastro-oesophageal junctionthe area where the oesophagus and the stomach meet (GOJ) cancer, also known as oesopho gastric junctional cancer, is a rare type of malignancy developing from the gastro-oesophageal junction, the area where the stomach and the oesophagus (food pipe) meet. This type of cancer is often difficult to diagnose, and may be misdiagnosed as stomach or oesophageal cancer. For more information on GOJ, please refer to the Rare Cancers Australia Gastro-oesophageal Junction Cancer page.
Rare forms of Stomach Cancer
These forms of stomach cancer are very rare:
- Gastric carcinoid tumours.
- Gastric small cell carcinomas.
- Gastric squamous cell carcinomas.
Treatment
If stomach cancer is detected, it will be staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for stomach cancer may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Gastrectomycomplete or partial removal of the stomach.
- Lymphadenectomysurgical removal of lymph node(s).
- Surgery to insert a feeding tube (often required after surgery on the stomach), such as a gastronomy tube (G-tube)a feeding tube surgically inserted through an incision in the abdominal wall directly into the stomach to get fluids/food/liquids to and from the stomach or a nasogastric tube (NG tube)a thin, soft tube that goes in through the nose, down the throat, and into the stomach to get fluids/food/liquids to and from the stomach, also known as a NG tube.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Targeted therapymedication that targets specific molecular features of cancer cells.
- Immunotherapya treatment that uses a person's immune system to fight cancer.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
While the cause of stomach cancer remains unknown, some of the following factors may increase the riskthe possibility that something bad will happen of you developing the disease:
- Being over 60 years old.
- Having had a previous infectiona condition where harmful pathogens, such as bacteria, viruses or parasites, have entered the body of Helicobacter pylori (H. pylori).
- Having had a previous partial gastrectomy.
- Having a history of smoking tobacco.
- Low red blood cell levels.
- Having a family history of stomach cancer.
- Having certain genetic conditions, such as:
- Familial adenomatous polyposis (FAP).
- Lynch syndrome/Hereditary nonpolyposis colorectalrelating to the colon or rectum in the large bowel/intestine cancer (HNPCC)..
- Hereditary diffuse gastric cancer (HDGC).
- Proximal polyposis of the stomach (GAPPS).
- Chronica long-lasting disease that changes slowly over time inflammation of the stomach (also known as chronic gastritis).
- Being overweight or obese.
- Excessive alcohol consumption.
- Having a diet with high salt content.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
Symptoms of a stomach cancer may include:
- Unexplained weight loss and/or loss of appetite.
- Difficulties swallowing.
- Indigestion, which may carry its own set of symptoms:
- Abdominal pain/burning.
- Heartburn.
- Frequent burping.
- Reflux.
- Nauseato feel sick or likely to vomit and/or vomiting.
- Abdominal pain.
- Feeling full after eating small quantities of food.
- Abdominal swelling and/or bloating.
- Fatiguea state of extreme tiredness or exhaustion, can be physical or mental.
- Anaemiaa condition where there aren't enough red blood cells in the blood, causing fatigue, weakness and pale skin and affecting how the body responds to infection.
- Vomit with blood in it.
- Discoloured stools.
Not everyone with the symptoms above will have cancer, but see your general practitioner GP if you are concerned.
Diagnosis
If your doctor suspects you have a stomach cancer, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- PET (positron emission tomography) scana type of medical imaging that uses radioactive tracers to create detailed images of the body.
- Ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Barium studiesa type of x-ray where barium powder is either swallowed (barium swallow) or introduced via the colon (barium enema) to coat the organs of the digestive tract and provide clearer x-ray images.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Endoscopya procedure that involves inserting a long, flexible tube with a light and small camera (endoscope) into the body to view internal organs.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
