Stomach cancer

About the stomach

The stomach is a hollow, muscular organ, which is shaped like a pouch. It is part of the digestive system, which helps your body break down food and turn it into energy.

The top of the stomach connects to the end of the oesophagus (food pipe). The bottom of the stomach connects to the start of the small bowel.

What is stomach cancer?

Stomach cancer develops when cells in any part of the stomach grow and divide in an abnormal way. Tumours can begin anywhere in the stomach, although most start in the stomach’s inner lining (mucosa). This type of cancer is called adenocarcinoma of the stomach or gastric cancer.

Stomach cancer can spread to nearby lymph nodes or to other parts of the body, such as the liver and lungs. It may also spread to the lining of the abdomen (peritoneum).

Other types of cancer can start in the stomach. These include small cell carcinomas, lymphomas, neuroendocrine tumours and gastrointestinal stromal tumours.

How common is stomach cancer?

About 2740 people are diagnosed with stomach cancer in Australia each year. Men are almost twice as likely as women to be diagnosed with stomach cancer. It is more common in people over 60, but it can occur at any age.

What are the symptoms?

Stomach cancer may not cause symptoms in the early stages. If there are symptoms, they can include:

• unexplained weight loss or loss of appetite
• difficulty swallowing
• indigestion – pain or burning feeling in the abdomen (heartburn), frequent burping, or stomach acid coming back up into the oesophagus (reflux)
• feeling sick and/or vomiting more often, with no apparent cause
• abdominal (belly) pain
• feeling full after eating, even a small amount
• swelling of the abdomen or feeling bloated
• unexplained tiredness
• vomit that has blood in it
• black or bloody faeces (stools or poo).

Not everyone with these symptoms has stomach cancer. If you have ongoing symptoms, see your general practitioner (GP).

What are the risk factors?

The exact causes of stomach cancer are not known. Below are some risk factors, but most people with these risk factors do not develop stomach cancer:

• being over 60 years
• infection of the stomach with the bacteria Helicobacter pylori (H. pylori)
• smoking tobacco
• low red blood cell levels related to a condition called pernicious anaemia
• a family history of stomach cancer
• having an inherited genetic condition such as familial adenomatous polyposis (FAP), Lynch syndrome, hereditary diffuse gastric cancer (HDGC), or gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS)
• inflammation of the stomach (chronic gastritis)
• being overweight or obese
• drinking alcohol
• eating a diet high in salt-preserved foods (e.g. processed meats, pickled vegetables)
• having part of the stomach removed for a non-cancerous condition.

Diagnosis

If your GP suspects that you have stomach cancer, they will examine you, arrange initial tests and refer you to a specialist such as a gastroenterologist.

• Endoscopy and biopsy -These are the main tests and are often done at the same time. An endoscopy (also called a gastroscopy or upper endoscopy) lets your doctor look inside your stomach and small bowel. A long, flexible tube with a light and small camera on the end (endoscope) will be passed into your mouth, down your throat and oesophagus, and into your stomach and small bowel. If the doctor sees anything unusual during the endoscopy, they may take a small sample of tissue. This is called a biopsy.

If a biopsy shows you have stomach cancer, you may have more tests to see if the cancer has spread (staging):

• Blood tests – a sample of your blood is checked. Checks your general health, checks for low red blood cell count (anaemia), and sees how your liver and kidneys are working.
• Imaging scans – pictures of the inside of your body using CT, MRI or PET–CT scans, to check if the cancer has spread to other parts of your body.
• Laparoscopy – keyhole surgery using a thin tube with a camera, to check if cancer has spread to the stomach’s outer layer or the abdomen lining.
• Genomic testing – special tests on tissue removed during surgery. Finds gene changes (mutations) in cancer cells, which helps decide which treatments may work best.
• Endoscopic ultrasound (EUS) – you may have an EUS at the same time as a standard endoscopy. The doctor will use an endoscope with an ultrasound probe on the tip or with a built-in ultrasound device. This test helps work out whether the cancer has spread into the oesophageal or stomach wall, nearby tissues or lymph nodes.

Some tests may be repeated during or after treatment to check your health and how well treatment is working.

Sometimes an endoscopic resection is used to help stage stomach cancer, but it can also be a treatment for early-stage stomach cancer.

Stomach cancer stages

Working out how far the cancer has spread is called staging. It helps your doctors recommend the best treatment for you.

The TNM staging system is used to stage stomach cancer. TNM stands for “tumour, node, metastasis”. T shows how big the tumour is (T1–T4), N shows if lymph nodes have cancer (N0–N3), and M shows if the cancer has spread to other parts of the body. Lower numbers mean the cancer is less advanced.

The TNM scores are combined to work out the overall stage of the cancer, from stage 1 to stage 4. Ask your doctor to explain what the stage of the cancer means for you. The stages of stomach cancer are:

• Stage 1 – early cancer; tumours only in the stomach
• Stages 2-3 – locally advanced cancer; tumour has spread deeper into the stomach wall and to nearby lymph nodes
• Stage 4 – metastatic or advanced cancer; tumours have spread beyond the stomach wall to nearby parts of the body or lymph nodes, or to more distant lymph nodes and other parts of the body.

Treatment for stomach cancer

Your health care team will recommend treatment based on where the cancer is in the stomach, and whether it has spread (the stage). Treatment will also depend on your age, medical history and general health.

You might feel confused or unsure about your treatment options and decisions. It’s okay to ask your treatment team to explain the information to you more than once. It’s often okay to take some time to think about your decisions.

Surgery is often part of the treatment for stomach cancer that has not spread. For early-stage cancer, you may only need to have an endoscopic resection. If the cancer has spread, treatment may include chemotherapy, targeted therapy, immunotherapy or radiation therapy.

Surgery

Surgery aims to remove all of the stomach cancer while keeping as much of the stomach as possible. The surgeon will also remove some healthy tissue around the cancer to reduce the risk of it returning.

Different types of surgery can be used depending on where the cancer is in the stomach:

• subtotal or partial gastrectomy – only part of the stomach is removed when the cancer is in the lower part of the stomach. If necessary, nearby fatty tissue (omentum) and lymph nodes are also removed. A small part of the upper stomach attached to the oesophagus is usually left in place.
• total gastrectomy – the whole stomach is removed when the cancer is in the upper or middle part of the stomach. Nearby fatty tissue (omentum), lymph nodes and parts of nearby organs, if necessary, are also removed. The surgeon rejoins the oesophagus to the small bowel.
• lymph node dissection – also called lymphadenectomy, lymph nodes are removed from around your stomach to reduce the risk of the cancer coming back and to help in the staging of the cancer.
• endoscopic resection – if you are diagnosed with very early stomach cancer, you may have an endoscopic resection. This aims to remove the whole tumour during the endoscopy so further treatment is not needed.

The surgery will be done under a general anaesthetic, and may be performed as an open surgery (laparotomy), keyhole surgery (laparoscopy) or robotic surgery.

Chemotherapy

Chemotherapy uses drugs to kill or slow the growth of cancer cells. For stomach cancer, it is used:

• before surgery (neoadjuvant chemotherapy) – to shrink large tumours and destroy any cancer cells that may have spread
• after surgery (adjuvant chemotherapy) – to reduce the chance of the cancer coming back
• as palliative treatment – to help control the cancer and improve quality of life

Targeted therapy

Targeted therapy is a drug treatment that works by blocking specific features of cancer cells. This helps stop the cancer from growing and spreading.

Targeted therapy is sometimes used to treat advanced stomach cancer. This treatment is usually given with chemotherapy every few weeks through a drip into a vein.

Immunotherapy

Recent advances in treating advanced stomach cancer include immunotherapy drugs called checkpoint inhibitors. These use the body’s own immune system to fight cancer.

Radiation therapy

Also known as radiotherapy, this treatment uses a controlled dose of radiation, such as focused x-ray beams, to kill or damage cancer cells. Radiation therapy for stomach cancer is commonly used to control bleeding.

Side effects of cancer treatments

All cancer treatments can have side effects. Your treatment team will discuss these with you before you start treatment. Talk to your doctor or nurse about any side effects you are experiencing.

Some side effects can be upsetting and difficult, but there is help if you need it. Call Cancer Council Victoria Tel. 13 11 20 or contact cancer support to speak with a caring cancer nurse for support.

Having a feeding tube

Some people with stomach cancer may need a feeding tube before, during or after treatment. This helps keep your weight steady and gives your body strength.

A feeding tube can go into your stomach or small bowel. It may be put in through your nose (nasogastric or nasojejunal tube) or through your belly with a small operation (gastrostomy or jejunostomy tube).

Many people find that having a feeding tube is a more comfortable way to get enough food and drink if the cancer is making eating and drinking difficult. Your health care team will show you how to keep the tube clean and working well. The doctor will remove the tube when you no longer need it.

Palliative treatment

Many people think that palliative care is for people at the end of life, but it can help at any stage of advanced stomach cancer. It helps to improve people’s quality of life by managing the symptoms of cancer without trying to cure the disease.

The treatment you are offered will be tailored to your individual needs. It may include surgery, radiation therapy, chemotherapy or other medicines. These treatments can help manage symptoms such as pain, bleeding, difficulty swallowing and nausea. They can also slow the spread of the cancer.

Follow-up appointments

You will have regular appointments to monitor your health, manage any long-term side effects and check that the cancer has not come back or spread.

During these check-ups, you may have blood tests, imaging scans or an endoscopy if needed. You will be able to discuss how you’re feeling and any concerns you may have. How often you need to see your doctor will depend on the level of monitoring needed for the type and stage of the cancer you had.

You should also see a dietitian for advice about good nutrition. For some people, stomach cancer does come back. This is known as a recurrence. If this happens, you may have further treatment, including chemotherapy, radiation therapy or surgery.

Support for carers, family and friends of someone with stomach cancer

Caring for someone with cancer can be difficult sometimes. If you are caring for someone with stomach cancer, these organisations can help:

• Cancer Council Victoria Tel. 13 11 20
• Carer Gateway Tel. 1800 422 737
• Carers Australia Tel. 1800 242 636

Where to get help

• Your GP (doctor)
• Your treatment team
• Cancer Council Victoria Tel. 13 11 20
  • Information and support line Tel. 13 11 20 (or Tel. 13 14 50 for an interpreter)
  • Stomach cancer
  • Cancer Council Victoria, My Cancer Guide - Find support services that are right for you.
• WeCan website – helps people affected by cancer find the information, resources and support services they may need following a diagnosis of cancer