Stomach cancer: Causes, symptoms, and treatments (original) (raw)

Stomach or gastric cancer involves a tumor that starts in any part of the stomach. Risk factors include smoking, genetic factors, and H. pylori infection. Stomach cancer symptoms include frequent burping and fatigue.

According to the World Health Organization (WHO), stomach cancer, or gastric cancer, caused 769,000 deaths worldwide in 2020. It is the sixth most common cancer worldwide and the third-leading cause of cancer-related deaths.

In the United States, the number of new stomach cancer diagnoses has fallen by around 1.5% annually for the past decade.

Around 90–95% of all stomach cancers are gastric carcinomas, or adenocarcinomas. In this type, cancer develops from the cells that form in the mucosa. This is the lining of the stomach that produces mucus.

This article discusses how to recognize, diagnose, and treat stomach cancer, as well as the risk factors for developing stomach cancer.

Stomach cancer symptoms can vary. At the same time, these symptoms may not appear for many years because stomach cancers can grow very slowly.

For this reason, many people with stomach cancer do not receive a diagnosis until the disease is already advanced.

What are the first signs of stomach cancer?

Early stage symptoms of stomach cancer may mimic other conditions such as stomach ulcers. They include:

• a sensation of being very full during meals
• swallowing difficulties
• feeling bloated after meals
• frequent burping
• heartburn
• indigestion that does not resolve
• stomach ache
• pain in the breastbone
• trapped wind
• vomiting, which may contain blood

Many of these symptoms are very similar to those of other, less serious conditions. However, anyone with an increased risk for stomach cancer who experiences swallowing difficulties should seek prompt medical treatment.

What are the advanced symptoms of stomach cancer?

As stomach cancer becomes more advanced, people may experience the following symptoms:

• anemia
• a buildup of fluid in the stomach, which may cause the stomach to feel lumpy to the touch
• black stools that contain blood
• fatigue
• loss of appetite
• weight loss

While it is not always clear what causes stomach cancer to develop, certain factors may increase the risk of developing this cancer. These include medical conditions such as:

• H. pylori infection in the stomach
• intestinal metaplasia, in which cells that would usually line the intestine line the stomach lining
• peptic stomach ulcers
• chronic atrophic gastritis, or long-term stomach inflammation that makes the stomach lining thinner
• pernicious anemia, which can develop due to a deficiency of vitamin B12
• stomach polyps

Certain genetic conditions also add to the risk of stomach cancer, including:

• Li-Fraumeni syndrome
• familial adenomatous polyposis (FAP)
• Lynch syndrome
• type A blood

Additional factors that can raise the risk of stomach cancer include:

• Smoking: Regular, long-term smokers have a greater risk of stomach cancer compared with nonsmokers. Read more on how to quit smoking here.
• Family history: Having a close relative who has had stomach cancer can increase the risk.
• Diet: People who regularly eat salted, pickled, or smoked foods have a higher risk of developing gastric cancer. A high intake of red meat and refined grains may also increase the risk. Foods that contain substances with links to cancer can also put a person at risk. For example, some studies have linked aflatoxins to cancer in some animals. Aflatoxins may, occasionally, exist in a variety of foods.
• Age: The risk of developing stomach cancer increases significantly after the age of 50 years. According to the American Cancer Society, 60% of people who receive a stomach cancer diagnosis are at least 65 years old.
• Sex: Men are more likely to get stomach cancer than women.
• Surgeries: Surgery to the stomach or a part of the body that affects the stomach, such as ulcer treatment, can increase the risk of stomach cancer years later.

People who experience symptoms and have one or more of these risk factors should see their doctor for a consultation.

Treatment for stomach cancer depends on several factors, including the severity of the person’s cancer and the individual’s overall health and preferences.

• Surgery: Doctors may need to surgically remove the stomach cancer as well as a margin of healthy tissue. Possible types of surgery include endoscopic mucosal resection, subtotal gastrectomy, and total gastrectomy.
• Radiation therapy: A specialist uses radioactive rays to target and kill cancerous cells. This type of therapy is not common in stomach cancer treatment. However, it may be necessary if the cancer is advanced or causes severe symptoms or as a way to help shrink the stomach tumor before surgery.
• Chemotherapy: This is a specialist treatment that uses drugs known as cytotoxic medicines to stop rapidly growing cancer cells from dividing and multiplying. Chemotherapy is a primary treatment for stomach cancer that has spread to distant sites in the body. A cancer care team may also administer chemotherapy to shrink the tumor before surgery or kill the remaining cancer cells after surgery.
• Targeted medications: These therapies recognize and attack specific proteins that cancer cells produce. Cancer care teams administer two targeted medications for people with stomach cancer through an intravenous (IV) infusion. They are Trastuzumab (Herceptin) and Ramucirumab (Cyramza).
• Immunotherapy: This is a treatment that uses medicines to encourage the body’s immune cells to attack cancer cells. People with advanced stomach cancer who have received two or more other treatments are candidates for immunotherapy.

Individuals with persistent symptoms of stomach cancer should see their doctor as soon as possible.

The doctor will ask about their symptoms, family history, and medical history, as well as lifestyle choices, such as what they eat and drink and whether they smoke. They will also carry out a physical examination to check for stomach tenderness or lumpiness.

They may also perform blood tests to identify whether there is an excess of certain substances that indicate cancer, including a complete blood count (CBC) to measure the number of red and white blood cells, as well as platelets and hemoglobin.

If the doctor suspects stomach cancer, they will refer the individual to a specialist in stomach diseases for tests. This specialist is known as a gastroenterologist.

Diagnostic measures include the following:

• upper endoscopy
• CT scan
• barium swallow

There is no way to prevent stomach cancer entirely.

However, a person can take steps to reduce the risk of developing the disease. These include the following:

Diet

Several dietary measures can help reduce the risk of stomach cancer.

The American Cancer Society suggests that eating at least two and a half cups of fruits and vegetables every day can help limit the risk.

It also recommends reducing the quantity of pickled, salted, and smoked foods in the diet. Switching out refined grains for whole-grain cereals, bread, and pasta and replacing red or processed meats with beans, fish, and poultry can also reduce a person’s chance of developing stomach cancer.

Smoking

Smoking tobacco may increase the risk of cancer developing in the part of the stomach near the esophagus.

Those who smoke should seek advice on quitting. People who do not already smoke should avoid exposure to tobacco smoke.

Taking nonsteroidal anti-inflammatory drugs (NSAIDs)

Using NSAIDs, such as aspirin, naproxen, or ibuprofen, may reduce the risk of stomach cancer. However, they carry additional risks, such as life threatening internal bleeding.

Only take NSAIDs to treat other conditions, such as arthritis. Do not take them solely to reduce the risk of stomach cancer.

Testing for other conditions and cancers

Individuals who have hereditary diffuse gastric cancer syndrome and Lynch syndrome have a drastically increased risk of stomach cancer. Recognizing these and taking precautions after receiving a doctor’s advice can reduce the risk.

People with close family members who have had stomach cancer and those who had invasive lobular breast cancer before the age of 50 years may benefit from genetic testing.

If a test shows changes in the CDH1 gene, a doctor may recommend removing the stomach before cancer develops.

Current research is looking into the possible cancer links of chronic Helicobacter pylori (H. pylori) infection in the stomach lining.

Early studies suggest that treating H. pylori infection with antibiotics can reduce the risk of stomach cancer, although further research is necessary.

Below, we answer some common questions about stomach cancer.

What is the stomach cancer survival rate?

Stomach cancer has a 5-year relative survival rate of 70%. This means that people with stomach cancer are 70% as likely, on average, to survive for 5 years after diagnosis as people who do not have stomach cancer.

How fast does stomach cancer spread?

Stomach cancer generally grows slowly. It can take a year or longer to develop. Research shows that it can also take just over a year from diagnosis for cancer to spread to other parts of the body, though this likely varies from person to person.

What is the difference between stomach cancer in female vs. male people?

A person’s sex will not influence the symptoms of stomach cancer. However, men are more likely to develop it than women.

The outlook after receiving a stomach cancer diagnosis is generally poor. The relative 5-year survival rate reduces as cancer becomes more aggressive and spreads beyond the original stomach tumor.

If cancer metastasizes into deeper tissues in the stomach, this rate falls to 32%. Once the stomach cancer reaches distant organs, the survival rate drops to 6%. For this reason, early diagnosis is key to improving the outlook for people with stomach cancer.