You may have heard of Helicobacter pylori, or H. pylori before but you may not know exactly what they are. H. pylori is a type of bacteria that can reside in your stomach and sometimes lead to an infection. While most people with H. pylori experience no symptoms, it can lead to stomach ulcers or even stomach (gastric) cancer in some.

Here’s what you need to know about the link between H. pylori and stomach cancer risk.

What is Helicobacter Pylori?

H. pylori is a spiral-shaped bacterium that was first discovered in the 1880s, but it wasn’t until the 1980s that researchers realised that this type of bacteria could be responsible for causing stomach ulcers. We now know that H. pylori is present in the stomachs of about half of the world’s population, and it’s thought to be acquired during childhood. While it remains harmless in most individuals, in some, it can lead to gastritis (inflammation of the lining of the stomach), ulcers, or even stomach cancer.

Can H. Pylori Cause Cancer?

Helicobacter pylori is a bacterium, generally a known risk factor for developing gastric ulcers, which can lead to gastric cancer if untreated. It has a complex relationship with cancer, particularly stomach cancer and a type of non-Hodgkin lymphoma known as mucosa-associated lymphoid tissue (MALT) lymphoma.

This correlation between H. pylori and stomach cancer stems from its ability to cause chronic inflammation of the stomach lining. Over time, this inflammation can lead to gastritis and, in some cases, escalate to gastric cancer.

However, while the presence of H. pylori is widespread in Singapore, increasing notably with age, not everyone infected with H. pylori will develop cancer, according to the Ministry of Health. And despite its potential to increase cancer risk, it's crucial to remember that the development of cancer from H. pylori is influenced by multiple factors, including genetics, lifestyle, and environmental factors.

How Does H. Pylori Cause Cancer?

The pathway from H. pylori infection to stomach cancer is not straightforward but involves several stages of disease progression.

Initially, H. pylori may cause no symptoms; however, over the years, it can lead to severe chronic atrophic gastritis (SCAG), an advanced form of stomach inflammation that significantly increases the risk of gastric cancer. This bacterium specifically affects the stomach lining by causing ulcers and persistent irritation, which can spur changes in the stomach cells.

Research also suggests that certain strains of H. pylori are more carcinogenic than others, meaning they have a higher potential to cause cancer.

How Long After Having H.Pylori Can You Get Stomach Cancer?

Naturally, one of the common questions regarding H. pylori is about its potential to develop into cancer.

The transition from an H. pylori infection to stomach cancer involves multiple factors, including the characteristics of the bacteria itself. This is because certain strains of H. pylori produce a toxin known as CagA, which disrupts normal cell functions and can promote cancerous changes by causing chronic inflammation and altering cell growth controls.

The likelihood of developing stomach cancer from H. pylori also depends on individual lifestyle choices and dietary habits. For instance, smokers with H. pylori infection are at a higher risk compared to non-smokers. Additionally, diets high in salt and processed meats can exacerbate the risk. Furthermore, studies indicate that even after successful treatment of H. pylori, the risk of developing gastric cancer can persist for up to 10 years, emphasising the importance of regular monitoring and healthy lifestyle choices post-treatment.

How to Identify if You Have H. Pylori

Many individuals infected with H. pylori experience no symptoms, making the infection particularly stealthy. However, for those who do exhibit symptoms, they often include discomfort or pain in the upper abdomen, which might be worse on an empty stomach. Individuals with this condition often experience a burning or gnawing discomfort in their upper abdomen that fluctuates over time. Other potential signs include bloating, frequent burping, loss of appetite, nausea, and unexpected weight loss.

In more severe cases, symptoms could escalate to include severe stomach pain that doesn't go away, difficulty swallowing, bloody or black tar-like stools, or vomiting that resembles coffee grounds. These symptoms suggest more serious conditions, such as ulcers or gastric bleeding, and require immediate medical attention.

If you suspect an H. pylori infection, it's essential to consult your doctor, who can recommend appropriate tests. These might include a breath test, stool test, or even an endoscopy to directly observe the stomach lining and possibly take a biopsy.

Early detection is key, as with any type of infection or cancer risk.

Diagnosing H. Pylori: What Are Your Options?

When it comes to diagnosing an H. pylori infection, several reliable methods can confirm whether you have this bacterium. If you're experiencing any of the aforementioned symptoms or if your doctor suspects H. pylori might be the cause of your gastric distress, the following tests can help determine the presence of the infection:

• Blood Tests: While a blood test can detect antibodies to H. pylori, indicating past or present infection, it cannot distinguish between an active and a resolved infection.
• Stool Tests: This method detects antigens associated with H. pylori in your faeces and is useful not only for diagnosing active infections but also for confirming the eradication of the bacterium post-treatment.
• Urea Breath Tests: This non-invasive test is highly effective. You'll be asked to drink a liquid containing a substance that H. pylori can break down. Afterwards, you'll breathe into a bag, and the air you exhale will be analysed for specific chemicals produced by the bacterial activity.
• Endoscopy: For those with severe symptoms or at higher risk of stomach cancer, an endoscopy might be recommended to examine the stomach lining directly and take tissue samples.

Stomach Cancer Causes

Stomach cancer is also known as gastric cancer. It is a cancer that begins in the lining of the stomach and is most common in Japan, Korea, and China, where incidences are more than 10 times higher than in Western countries.

In Singapore, stomach cancer ranks as the 8th most common cancer among males and the 10th among females, typically affecting men and individuals aged between 50 and 70 years old, according to SingHealth. The exact cause of stomach cancer is not fully understood, but there are several risk factors that have been identified. These include infection with the H. pylori bacteria; a diet high in salt and low in fruits and vegetables; smoking; and exposure to certain chemicals.

Understanding the Risk Factors for Stomach Cancer

While the precise origins of stomach cancer are yet to be fully understood, certain risk factors have been consistently associated with its development. These include:

• Chronic Infection: H. pylori, the stomach bacterium that is linked to causing chronic gastritis and stomach ulcers.
• Dietary Habits: A diet high in salted, cured, smoked, or pickled foods and low in fresh fruits and vegetables.
• Lifestyle Choices: Smoking and excessive alcohol consumption.
• Family History and Genetics: Conditions like familial adenomatous polyposis (FAP).
• Medical Conditions: Certain medical issues, including chronic anaemia (such as megaloblastic and pernicious anaemia), previous stomach surgeries, and conditions like atrophic gastritis, which reduce stomach acid production, are linked to higher risks.
• Stomach Polyps: These benign growths can sometimes progress to cancer if left unchecked.

These risk factors, while providing insights into potential triggers for stomach cancer, do not guarantee that someone will develop the disease.

Stomach Cancer Symptoms

In Singapore, individuals diagnosed with stomach cancer without metastases, who have undergone complete surgical removal of the tumour and associated lymph nodes, have a five-year survival rate ranging from 26% to 95%. This variance highlights the importance of early detection and appropriate treatment strategies.

Awareness of stomach cancer symptoms is crucial because early intervention can significantly improve outcomes. Common signs include:

• Persistent abdominal pain and discomfort
• Indigestion
• Heartburn
• Bloating,
• Nausea and vomiting
• Weight loss
• Fatigue

If you experience any of these symptoms on a regular basis, it is crucial to see your doctor so that he or she can rule out other potential causes.

Diagnosing Stomach Cancer

Stomach cancer diagnosis often starts with recognising symptoms that prompt further investigation. Medical professionals typically diagnose this condition with:

• Upper Endoscopy (Gastroscopy): An endoscope is inserted through the mouth to examine the stomach lining for abnormalities. If suspicious areas are found, a biopsy may be performed during the same procedure.
• Barium Meal X-ray: Patients consume a barium-containing liquid that coats the stomach lining, making it visible on X-rays to highlight abnormalities.
• Faecal Occult Blood Test: This test looks for hidden blood in your stool, which could suggest bleeding somewhere in your digestive system.

For those diagnosed with stomach cancer, further tests determine the cancer's spread and stage:

• CT Scan: Provides an image of the stomach and other areas, helping to identify whether the cancer has spread.
• PET Scan: Uses radioactive material to create detailed 3-D images. While effective, it might not detect all types of stomach cancer due to their varied characteristics.
• Exploratory Surgery: Particularly through laparoscopy, this procedure allows doctors to look inside the abdomen to see if the cancer has spread beyond the stomach.

Treatment for Stomach Cancer

If stomach cancer is caught early, it may be treated with surgery to remove the cancerous tissue. However, additional treatments, such as chemotherapy or radiation therapy, may be necessary, especially if the cancer has spread to other parts of the body. Some patients may also receive targeted therapy, which uses drugs that specifically target cancer cells. Most recently, immunotherapy has also emerged as another option for treatment. In many cases, the cancer can be cured if it is caught early enough.

However, it's crucial to understand that the most appropriate treatment plan is influenced by various factors, including the size, location, and stage of the tumour at diagnosis, as well as the patient's overall health.

It is thus important to work with a team of experienced medical professionals to ensure the best possible treatment plan and outcome.

Choose A Comprehensive Cancer Care Provider

Early detection and treatment is vital for stomach cancer. At OncoCare, our team of cancer specialists provide appropriate tests, workups, and a full diagnosis, for your peace of mind. With experience in diagnosing and treating stomach cancer, we are able to advise on the optimal treatment options for each patient.

Schedule an appointment today at one of our conveniently located clinics.

Explore our resources such as "Is Your Love for Spicy Food Putting You at Risk for Stomach Cancer?" and "Dealing With Cancer Pain" to further understand your risks and the support available.

“Expert knowledge means better care for cancer”

Written by:
Dr Thomas Soh
MBBS (Singapore)
MRCP (United Kingdom)