Stomach cancer, also known as gastric cancer, is a disease that develops over many years and begins when malignant (cancerous) cells form in the lining of your stomach.
The wall of a person’s stomach has 5 layers of tissue, and cancer begins in the inner most layer called the mucosa and then spreads out to the various layers as the tumour grows.
These layers play a huge role in determining the extent or stage of stomach cancer.
There are 5 stages used to distinguish the severity of stomach cancer, which can be identified using the TNM System.
The TNM system is the use of diagnostic tests to determine the following:
- The tumour and how deeply the primary tumour have spread into the stomach wall.
- The Node and whether the tumour has spread into the lymph nodes.
- The Metastasis – if the cancer has spread to other parts of the body
Types of stomach cancer
- Adenocarcinoma makes up 90-95% of stomach cancers and develop from the cells that line the inner-most layer of the stomach, the mucosa.
- Lymphoma is a cancer of the immune system tissue, the lymphocytes, that is sometimes found in the wall of the stomach and treatment is dependent on the type of lymphoma.
- Gastrointestinal stromal tumour is a rare form of stomach cancer where the tumour begins in the interstitial cell of Cajal in the stomach wall. Some of these tumours remain benign while others are cancerous.
- Carcinoid tumours begin in the hormone producing cells in the stomach and usually do not spread to other organs.
- Other very rare cancers that may begin in the stomach include squamous cell carcinoma, small cell carcinoma and leiomyosarcoma (soft tissue sarcoma).
- Stomach cancer is the 5th most common cancer type worldwide.
- It is the 3rd most common cause of cancer deaths globally.
- 723,000 people worldwide will die from stomach cancer.
- 1 in 111 men and women will be diagnosed in their lifetime.
- There are 1 million new cases of stomach cancer each year.
Signs and Symptoms
Stomach cancer does not cause specific symptoms and is therefore not usually found at an early stage. Symptoms found may be vague and can include:
- Persistent indigestion or heartburn.
- Pain or discomfort in the abdomen.
- Nausea and vomiting (of solid food just after eating).
- Diarrhoea or constipation.
- Bloating of the stomach after meals.
- Loss of appetite.
- Sensation of food being stuck in your throat when eating.
Advanced stomach cancer may show the following symptoms:
- Weakness and fatigue.
- Vomiting blood.
- Blood in stool.
- Unexplained weight loss.
- Trouble swallowing.
- Yellowish eyes or skin.
- Swelling in your stomach.
- Constipation or diarrhoea.
The chances of recovery are higher when the gastric cancer is found early, however it is more often found when it is in its advanced stages. At this later stage the cancer may be treated, however it is rarely cured.
Screening for stomach cancer is not that common, however if you are at a higher risk, your doctor may be able to assist in ways to keep an eye out for it.
After a physical exam and a history of the patient’s health habits is taken into account, further tests that examine the stomach and oesophagus are used to detect and diagnose gastric cancer.
- Upper endoscopy.
- Upper GI series test.
- CT Scan or a PET-CT Scan.
- Biopsy (which can be done during an endoscopy).
- Complete blood count (CBC).
- Blood chemistry studies.
The cause of stomach cancer is not exactly known, however, your age, diet and stomach diseases such as the following increases the chances of developing stomach cancer:
- Infections with pylori, a common bacteria that causes ulcers.
- Inflammation in your gut known as gastritis.
- Pernicious anaemia where there is a decrease in red blood cells due the inability of the intestines to absorb Vitamin B12.
- A diet high is salt and smoked foods.
- A diet low in vegetables.
- Family history of stomach cancer.
Regular exercise, reducing your intake of salty and smoked foods and increasing your intake of fruit and vegetables are some of the preventative measure that can be taken to reduce your chances of being diagnosed with stomach cancer.
Treating stomach infections, eating healthy and not smoking also helps prevent stomach cancer. Also monitoring aspirin intake to avoid any negative effects on your stomach.
An important part of treatment is palliative (supportive) care which involves the relief of the symptoms shown by the patient. Palliative care is given just after diagnosis and is continued throughout the treatment.
There are various stages of stomach cancer, all of which can be treated based on the stage
A group of unhealthy cells detected that are not yet malignant can be removed in surgery by removing parts of the stomach as well as nearby lymph nodes.
A tumour can be found in the lining of your stomach and may have spread into your lymph nodes.
Surgery will be needed as well as chemotherapy or chemoradiation.
The cancer has spread to the deep layers in the stomach and surgery will be needed to remove the cancerous cells and lymph nodes nearby. Chemotherapy and chemoradiation will most likely be needed before and after surgery.
The cancer may be found in all layers of the stomach as well as other organs that are close by, such as the spleen or colon, or it may reach deep into your lymph nodes.
If the body is strong enough, surgery is needed to remove the entire stomach. Chemotherapy and chemoradiation will be needed and may help with easing the symptoms.
The cancer has spread to various other organs including the brain, liver and lungs and, is much harder to cure. Your doctor may help you manage the symptoms.
If the tumour blocks your gastrointestinal system you may need a gastric bypass to create a route around the tumour.
In addition to the surgical removal of the stomach as well as chemotherapy and chemoradiation therapy, targeted therapy may be used which has fewer side effects.
2. National Cancer Institute
3. American Cancer Society
6. Mayo Clinic