What Are the Different Types of Stomach Cancer?
There are many different types of stomach cancer, and knowing the type helps you and your medical team decide on the best treatment possible.
Adenocarcinoma: these tumors start growing in the gland cells in the inner lining of the stomach wall called the mucosa. Up to 95% of all stomach cancers are adenocarcinoma.
Other types of stomach cancer, which are rare, include:
Gastrointestinal stromal tumours (GISTs): a rare type of cancer called a soft tissue sarcoma, which is usually found in the cells of the stomach wall but can develop anywhere in the gastrointestinal tract.
MALT Lymphoma (extranodal marginal zone lymphoma): is a slow growing type of Non-Hodgkin’s Lymphoma — a cancer of the lymphatic system. These are cancers of the immune system tissue, which is also found in the wall of the stomach.
Carcinoid tumors (neuroendocrine tumors or NETs): these start in the neuroendocrine or hormone-making cells of the stomach.
Other rare types of cancer that can start in the stomach include: linitis plastica, squamous cell carcinoma and leiomyosarcoma.
What Are the Symptoms of Stomach Cancer?
Although stomach cancer is relatively rare compared to other types of cancer, it is often not diagnosed until it has spread to other parts of the body, making treatment more difficult. This is because some of the symptoms of stomach cancer are often symptoms of other more common conditions, such as stomach ulcers, and symptoms may vary depending on which type of you have.
There are some common indicators that need to be checked out as soon as possible to rule out stomach cancer. They include:
- Difficulty swallowing (dysphagia)
- Losing weight without trying to
- Feeling nauseous or being sick
- Finding a lump at the top of your tummy
- Heartburn or acid reflux
- Loss of appetite
- Indigestion and excessive burping or hiccuping
- Feeling full very quickly when eating
- Pain at the top of your tummy
- Feeling tired or breathless
- Dark stools or blood in your stools
- Low red blood count (anaemia)
- A high temperature (fever) and sweating at night
What Are the Causes of Stomach Cancer?
The causes of stomach cancer are unknown, but there are certain common risk factors that increase the chances of getting the disease.
Gender: stomach cancer is more common in men than women. Men are twice as likely to get it than women.
Age: the risk of stomach cancer increases as you get older. Over half the people diagnosed with stomach cancer are aged over 75.
Helicobacter Pylori (H.pylori) infection: a common stomach infection which, if left untreated, can cause inflammation and ulcers and increase the risk of stomach cancer.
Smoking: people who smoke tobacco increase their risk of developing stomach cancer.
Being very overweight or obese: having a BMI of over 30 indicates obesity, and this is a risk factor for stomach cancer.
Poor diet: not eating enough fruit and vegetables, having too much salt in your diet, eating a lot of processed meat and smoked or pickled foods, are all factors that may increase the chances of stomach cancer occurring.
Existing stomach conditions: some stomach conditions can cause changes in the stomach lining and increase the risk of stomach cancer. They include pernicious anemia (a condition where the body can’t make enough healthy red blood cells due to a lack of vitamin B12) and atrophic gastritis (chronic inflammation of the stomach lining).
Stomach surgery: previous surgery for another stomach condition may put someone at a slightly increased risk of stomach cancer. Removing part of the stomach decreases the amount of acid in the stomach, which lowers the protection from bacteria and increases the risk of stomach cancer occurring.
Family history: most stomach cancers are not inherited, but rarely stomach cancer runs in families. Sometimes family members share risk factors for stomach cancer, for example they may have H.pylori, but most people who develop stomach cancer do not have a family history of it.
Some people with neurofibromatosis may have a slightly increased risk of developing a GIST.
MALT lymphomas usually start in the stomach, where there has been long term inflammation; most commonly this is linked to an infection of bacteria called Helicobacter Pylori (H.pylori). If this is left untreated, it can cause long-term inflammation of the stomach lining and possibly lead to the development of MALT lymphoma.
People with a rare condition called Multiple Endocrine Neoplasia 1 (MEN1) have a higher risk of developing NETs.
Stomach Cancer Treatment
A team of specialists will discuss the treatment options. Treatment can vary and will depend on a variety of factors. These include how advanced the cancer is, how well the patient is and their own personal preference for what treatments they wish to undergo.
The main treatments for stomach cancer are:
Surgery: to remove the cancer or relieve the symptoms of stomach cancer that has spread.
Chemotherapy: anti-cancer drugs are used to destroy cancerous cells. It can be given on its own or in combination with other treatments.
Radiotherapy: uses high-energy rays to treat cancer and destroy cancer cells in a specific area. It can be given to shrink tumors, with chemotherapy after surgery to reduce the risk of the cancer returning or to help symptoms.
Targeted therapy: sometimes a targeted therapy drug called trastuzubab is given with chemotherapy to treat advanced stomach cancer. Targeted therapy drugs target something in or around the cancer cells that is helping them grow.
These treatments vary for the different types of stomach cancer:
GISTs: this type of cancer does not respond well to chemotherapy or radiotherapy. Most small GISTs are treated with surgery. If the tumor is large, you may have to have part or most of the stomach removed. GIST patients may also be advised to undergo targeted therapy (drugs which interfere with the way the cancer cells grow). They work by blocking signals in the cancer cells that make them grow. The common growth inhibitors are: imatinib (Glivec), sunitinib (Sutent) and regorafenib (Stivarga). Treatment with these drugs may help shrink the cancer or stop it from growing.
For people with MALT lymphomas, treatment will depend on the type of MALT and the stage it is in. If it is growing very slowly and not causing problems, then treatment may not be necessary; however, the situation will need to be monitored so that if anything changes, treatment can begin. If the patient has H.Pylori (a bacterial infection) then a course of two antibiotics and a treatment to reduce stomach acid will be required. This may clear all signs of the lymphoma, but it can take several months. Regular endoscopes will be required to check the lymphoma is shrinking and that no further treatment is required. Radiotherapy and chemotherapy may be necessary too.
For NETs the main treatment option is to perform surgery, which removes the tumor. If it can’t be fully removed, then treatment will aim to relieve symptoms and improve quality of life. Other treatments include close monitoring with regular check-ups, somatostatin analogues (drugs that treat the symptoms of carcinoid syndrome), chemotherapy to treat NETs that have spread and targeted therapies to block how the cancer cells grow and divide.