Gastric Cancer Causes, Types, Symptoms, Diagnosis, Treatment and FAQs

Gastric Cancer

The stomach is a muscular organ forming part of the digestive system. Food travels down the oesophagus and into the stomach to be mixed with acids and enzymes. About 600 people are diagnosed with stomach cancer (also known as gastric cancer) each year in Victoria.

Stomach cancer most commonly affects people in their late 60s to 70s, but it can, rarely, affect younger people as well. Stomach cancer affects almost twice as many men as women.

Incidence varies between countries around the world. Research suggests this can be explained to some extent by diet. Stomach cancer incidence is increased in people who eat a diet of very salty foods. The incidence of stomach cancer is very high in countries such as Japan where they eat a lot of very salty pickled foods.

These foods are not commonly eaten in Australia. Infection with the bacterium Helicobacter pylori (H. pylori) has also been shown to increase the risk of stomach cancer. Sadly, most people are diagnosed with stomach cancer when it is in its advanced stages.

However, this does not mean that treatment cannot help control cancer and relieve its symptoms.

Types of stomach cancer

The two main types of stomach cancer are:

adenocarcinoma – more than 95 per cent of stomach cancers are adenocarcinomas. Cancer starts in the gland cells that line the stomach
squamous cell cancer – cancer of the skin type cells that sit between the gland cells and the stomach lining.

Risks and causes of stomach cancer

The exact cause of stomach cancer is not known. However, risk factors that make a person more likely to develop this disease include:

smoking – research shows this doubles your risk of developing stomach cancer
age – most cases are diagnosed in people over 50 years old
gender – it is twice as likely in men than women
infection with the bacteria Helicobacter pylori increases the risk of stomach cancer
if a person has had a partial gastrectomy for ulcer disease (the person may develop stomach cancer about 20 years after having this procedure)
a genetic change (mutation in a gene) that causes a bowel disorder  the most common of which are:
- familial adenomatous polyposis (FAP)
- hereditary non-polyposis colorectal cancer (HNPCC).

There is a blood test or breath test to detect helicobacter infection and it can usually be cured with antibiotics. However, it is important to mention that millions of people are infected with these bacteria. Most of them will never get stomach cancer, which means there are other factors affecting risk.

A diet high in fresh fruit and vegetables seems to lower the risk of stomach cancer, while a diet high in preserved foods or very salty food increases risk.

Family history is being researched as a risk factor for stomach cancer. You have an increased risk if you have a first-degree relative with stomach cancer. However, it is not known whether this is a genetic issue, or due to sharing other risk factors, such as Helicobacter pylori infection.

Workplace factors may also play a part. For example, workers in the metal industry appear to be at higher risk.

Researchers are looking into other risk factors such as family history, radiation exposure and regularly taking non-steroidal anti-inflammatory drugs (NSAIDs), but as yet, there are no results from further long-term clinical trials.

Symptoms of stomach cancer

The symptoms of stomach cancer are usually vague and can be common to other medical conditions. For this reason, stomach cancer is usually diagnosed in the advanced stages of the disease.

Symptoms can include:

indigestion (such as heartburn, bloating or burping)
feeling full, even after a small meal
nausea or vomiting (or both)
pain and difficulty swallowing
unexplained tiredness or weakness
blood in vomit
black-coloured faeces, which is a sign of old blood
weight loss or loss of appetite – more likely in very advanced cancer.

Diagnosis of stomach cancer

Stomach cancer is usually diagnosed using a number of tests, including:

gastroscopy – a doctor passes a thin flexible tube down your throat so they can see into your stomach, oesophagus and the upper part of your bowel
biopsy – a doctor removes a small sample of your stomach during an endoscopy, and looks at it under a microscope
barium x-ray (occasionally) – you swallow liquid barium, which shows up on an x-ray screen as it passes through your stomach and digestive system. This can reveal abnormalities in your stomach
ultrasound – sound waves create a picture of your stomach
blood tests – these include a carcinoembryonic antigen (CEA) test. CEA is produced in high quantities by some cancer cells. This occurs in about half of the people diagnosed with stomach cancer.

If you are diagnosed with stomach cancer, you may need further tests to see if cancer has spread. These may include:

computed tomography (CT) scan – a special x-ray taken from many different angles to build a three-dimensional picture of your body. A dye may be injected to highlight internal organs
magnetic resonance imaging (MRI) scan – similar to a CT scan, but it uses a powerful magnet and magnetic field instead of x-rays to build three-dimensional pictures of your body
positron emission tomography (PET) scan – a doctor gives you an injection of a glucose solution containing a very small amount of radioactive material. The scanner can ‘see’ the radioactive substance. Cancerous cells show up as ‘hot spots’ (areas where the glucose is being taken up).

Treatment of stomach cancer

Treatment depends on the type and size of cancer, your age and health, and whether cancer has spread. Treatments include:

surgery – this is the main treatment in the early stages. All or part of your stomach is removed along with any cancerous lymph nodes. This is major surgery and you will need to be fit enough to have it
chemotherapy – anti-cancer medications can stop cancer cells from multiplying. You may have this before or after surgery
radiotherapy – radiation can kill cancer cells. Radiotherapy is not often used to treat stomach cancer, but you may receive it after surgery to destroy any remaining cancer cells or – if the cancer is very advanced – to help relieve pain
complementary and alternative therapies – it’s common for people with cancer to seek out complementary or alternative treatments. When used alongside your conventional cancer treatment, some of these therapies can make you feel better and improve your quality of life. However, others may not be so helpful and in some cases may be harmful. It is important to tell your healthcare professional about any complementary medicines you are taking, and never stop taking your conventional treatment without consulting your doctor first. Cancer Australia has a factsheet about complementary and alternative therapies.

All treatments have side effects. These will vary depending on the type of treatment that you are receiving. Many side effects are temporary, but some may be permanent. Your doctor will explain all the possible side effects before your treatment begins.

Your sexuality and stomach cancer

Having stomach cancer and its treatment can affect the way you feel about your body, including who you are, your relationships, the way you express yourself sexually and your sexual feelings (your ‘sexuality’). These changes can be very upsetting.

Your medical team should discuss these issues with you before and during your treatment. If you feel you would like to discuss things further, ask your doctor for a referral to a counsellor or call the Cancer Council on 13 11 20 for information and support.

Caring for a person with stomach cancer

Caring for someone who has cancer can be a difficult and emotional time. If you or someone you know is caring for someone with stomach cancer, there is support available from the Cancer Council Victoria.

When a stomach cancer cure isn’t possible

If a person’s stomach cancer has been diagnosed in its later stages, their cancer may have spread to the point where a cure is no longer possible. Treatment then focuses on improving the person’s quality of life by relieving the symptoms (this is called palliative treatment).

This may include surgery to relieve a blockage at the entry or exit of the person’s stomach, or medications to relieve pain, nausea and vomiting. Information and support can be found at Cancer Council Victoria.

Tests that examine the stomach and esophagus are used to detect (find) and diagnose gastric cancer.

The following tests and procedures may be used:

Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease in the organ or tissue that produces it.
Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
- The number of red blood cells, white blood cells, and platelets.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the sample made up of red blood cells.
Upper endoscopy: A procedure to look inside the esophagus, stomach, and duodenum (first part of the small intestine) to check for abnormal areas. An endoscope (a thin, lighted tube) is passed through the mouth and down the throat into the esophagus.
Barium swallow: A series of x-rays of the esophagus and stomach. The patient drinks a liquid that contains barium (a silver-white metallic compound). The liquid coats the esophagus and stomach, and x-rays are taken. This procedure is also called an upper GI series.
CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
Biopsy: The removal of cells or tissues so they can be viewed under a microscope to check for signs of cancer. A biopsy of the stomach is usually done during the endoscopy.

One or more of the following tests may be done on the samples of tissue that are removed:

Immunohistochemistry study: A laboratory test in which a substance such as an antibody, dye, or radioisotope is added to a sample of cancer tissue to test for certain antigens. This type of study is used to tell the difference between different types of cancer.
FISH (fluorescence in situ hybridization): A laboratory technique used to look at genes or chromosomes in cells and tissues. Pieces of DNA that contain a fluorescent dye are made in the laboratory and added to cells or tissues on a glass slide. When these pieces of DNA bind to specific genes or areas of chromosomes on the slide, they light up when viewed under a microscope with a special light. The sample of blood or bone marrow is checked for HER2/neu to help decide the best treatment.

Frequently Asked Questions about Gastric Cancer

True. Lung cancer causes the largest number of cancer deaths in the U.S., but stomach cancer is common around the world. It is one of the leading causes of cancer-related deaths worldwide, particularly in less-developed countries. According to the World Cancer Research Fund International, it is the 5th most common cancer in the world. Also, the World Health Organization (WHO) reports that stomach cancer is the 4th most common cause of cancer death worldwide.

The U.S. used to have high rates of stomach cancer until then 1930s when widespread use of refrigeration made fruits and vegetables readily accessible and reduced the need for salted or smoked meats. The use of antibiotics to treat Helicobacter pylori (H. pylori) bacteria, a leading cause of stomach cancer, is also believed to have decreased rates in the U.S.

What are the major risk factors for developing stomach cancer?

Risk factors for developing stomach cancer include:

Gender: men are more likely to develop stomach cancer than women
Diet: eating few fruits and vegetables and/or high amounts of preserved meats increases risk
Infection: H. pylori bacteria are linked to stomach cancer
Age: over age 50
Ethnicity: stomach cancer is more common in Hispanic Americans, African Americans, and Asian/Pacific Islanders
Location: stomach cancer is more common in China, Japan, Eastern, and Southern Europe, and Central and South America
Smoking
Being overweight or obese

Stomach cancer is hereditary: True or False?

True. Stomach cancer can run in families. If you have a first-degree relative (parent, sibling, or child) with stomach cancer you may be more likely to develop the disease.

What blood type is most at risk for stomach cancer?

People with type A blood have an increased risk of developing stomach cancer. The reasons for this are unknown.

Why is stomach cancer rarely diagnosed early?

In the early stages, stomach cancer often does not present any symptoms. When symptoms do appear, they often resemble other medical conditions. Signs and symptoms of stomach cancer may include:

Loss of appetite
Indigestion/heartburn/stomach upset
Abdominal pain
Nausea/vomiting
Weight loss (without trying)
Bloating, especially after eating
Low red blood cell count (anemia)
Fatigue/weakness
Blood in stools

If you experience any of these symptoms, see a doctor.

How is stomach cancer diagnosed?

Stomach cancer diagnosis begins with a history and physical by your doctor. You may be referred to a gastroenterologist, a specialist in disorders of the digestive tract. An upper endoscopy may be ordered. This is a test where a long tube with a camera on the end is inserted down your throat into the stomach to visualize your upper digestive tract including the esophagus, stomach, and the upper part of the small intestine. A biopsy, or tissue sample, may be taken. An ultrasound may be used with the endoscope to produce images of the organs and help see how far stomach cancer has spread.

Which bacteria is commonly linked to stomach cancer?

Certain strains of Helicobacter pylori (H. pylori) are commonly associated with stomach cancer. About half the population has some type of H. pylori infection but most will not develop stomach cancer.

Stomach cancer can be treated by removing part of the stomach: True or False?

True. Removing the affected part of the stomach in a procedure called a gastrectomy can treat stomach cancer in the earliest stages when the cancer is limited to the inner lining layer of the stomach. Once cancer has spread it may be treated with gastrectomy, lymph node removal, chemotherapy, and/or radiation.

What is the average age of stomach cancer diagnosis?

The average age a person is diagnosed with stomach cancer is 69. About 60% of people diagnosed with stomach cancer are 65 or older. The majority of people diagnosed with stomach cancer are between their late 60s to their 80s.