Is Gastric Cancer Hereditary?

Gastric cancer, commonly known as stomach cancer, can be a devastating diagnosis. While not all cases of gastric cancer are hereditary, some are linked to genetic factors that can increase an individual’s risk. 

Understanding whether gastric cancer runs in families is essential for early detection and prevention, particularly for those with a family history of the disease. 

This article explores the hereditary nature of gastric cancer, factors influencing risk, and steps to reduce it.

What Is Gastric Cancer?

Gastric cancer originates in the stomach and typically develops over years.

Types of Gastric Cancer:

• Adenocarcinoma: The most common form, arising in the stomach’s inner lining.
• Lymphoma: Cancer originating in the stomach’s lymphatic tissue.
• Gastrointestinal Stromal Tumors (GISTs): Rare tumors in stomach wall cells.
• Carcinoid Tumors: Originating in hormone-producing stomach cells.

Causes and Risk Factors:

Gastric cancer has both genetic and environmental causes. Risk factors include age (typically over 50), Helicobacter pylori (H. pylori) infection, dietary habits, smoking, and obesity. While most cases are sporadic, a portion stems from inherited genetic mutations.

Globally, gastric cancer is one of the leading causes of cancer deaths, emphasizing the need to better understand its hereditary nature and other risk factors.

What Does ‘Hereditary’ Mean?

Hereditary diseases are passed down from parent to child through genetic material (DNA). This means that certain genetic mutations can be inherited, increasing the likelihood of developing specific conditions, like gastric cancer.

Hereditary vs. Non-Hereditary Gastric Cancer:

• Hereditary Gastric Cancer: Attributed to inherited genetic mutations and syndromes.
• Non-Hereditary Gastric Cancer: Caused by external factors like infections, diet, and lifestyle.

Some people with a genetic predisposition may never develop gastric cancer if environmental triggers are absent, while others with no family history may still develop the disease.

Is Gastric Cancer Hereditary?

While not all gastric cancers are hereditary, up to 1-3% of cases are linked to inherited genetic conditions.

1. Genetic Factors and Heredity

Some inherited genetic mutations are prominent risk factors for gastric cancer:

• Hereditary Diffuse Gastric Cancer (HDGC):

• Caused by mutations in the CDH1 gene.
• Leads to diffuse gastric cancer, often diagnosed in younger individuals.
• Women with CDH1 mutations also face a higher risk of lobular breast cancer.

• Lynch Syndrome:

• A genetic condition increasing the risk of several cancers, including colorectal and gastric cancer.
• Other Genetic Syndromes: Mutations in genes like TP53 (Li-Fraumeni Syndrome) and APC (Familial Adenomatous Polyposis) may also be associated with gastric cancers.

Studies estimate that individuals with CDH1 mutations face a 70-80% lifetime risk of developing gastric cancer.

2. Family History

Having a family history of gastric cancer significantly elevates risk:

• Individuals with one or more first-degree relatives (parent, sibling, child) diagnosed with gastric cancer are at a higher susceptibility.

• Family history might indicate either inherited genetic mutations or shared environmental and lifestyle factors.

3. Epigenetic Influences

Epigenetics refers to the interaction of environmental factors with gene expression:

• Environmental Triggers: Tobacco, alcohol, and poor diet may affect how inherited genes behave.
• Some people with a genetic predisposition develop cancer only when exposed to these triggers, showing the complex relationship between genes and environment.

Other Risk Factors for Gastric Cancer

Many cases of gastric cancer result from non-hereditary factors, including:

Helicobacter pylori (H. pylori):

• This bacterium infects the stomach lining, causing chronic inflammation that can progress to cancer.

• While H. pylori infection itself is not hereditary, some families may pass on immune system susceptibility to chronic infections.

Dietary Habits and Lifestyle Choices:

• High salt, smoked, or pickled food consumption increases risk.

• Low fruit and vegetable intake is another factor.

• Smoking and excessive alcohol use exacerbate the development of gastric cancer.

Obesity:

Excess weight can lead to gastroesophageal reflux disease (GERD), a condition linked to an increased risk of stomach cancer.

How to Determine Your Risk?

Awareness and assessment are crucial for individuals with a genetic predisposition or family history of gastric cancer.

1. Genetic Testing

• Genetic tests screen for mutations in genes like CDH1 or others linked to hereditary cancer syndromes.

  
  

• Recommended for individuals with:
  
  
• Multiple family members diagnosed with gastric or related cancers.
• Diagnoses of diffuse gastric cancer at a young age (before 40).
• Known familial mutations, such as CDH1.
• Benefits: Early identification of risk can enable preventative steps like regular screenings or prophylactic surgery.
• Limitations: Not all hereditary cancers are linked to identifiable gene mutations.

2. Screening for At-Risk Individuals

• Regular Endoscopies: For individuals with hereditary risk, endoscopies (starting in early adulthood) can detect cancer early.
• Monitoring Family History: Share family medical history with healthcare providers.

Prevention and Risk Reduction

Both genetic and non-hereditary factors can be managed to reduce risk:

For Those With Hereditary Risk:

• Healthy Diet: Limit salty, smoked, and processed foods; opt for a diet high in fruits, vegetables, and whole grains.
• Quit Smoking: Smoking cessation reduces risk significantly.
• Regular Checkups: Genetic counseling and routine screenings ensure early detection.
• Prophylactic Gastrectomy: Individuals with CDH1 mutations may opt for surgery to remove the stomach before cancer develops, a life-saving option for those at very high risk.

For the General Population:

• Prevent H. pylori infections through proper sanitation and prompt medical treatment of symptoms.
• Maintain a healthy weight and exercise regularly.

Symptoms of Gastric Cancer

Symptoms of gastric cancer often appear late, which is why early screenings for high-risk individuals are critical. Common symptoms include:

• Persistent indigestion or heartburn.

• Nausea and vomiting.

• Abdominal pain or bloating after meals.

• Unintentional weight loss.

• Fatigue or anemia caused by chronic blood loss.

Seek medical attention if you experience persistent symptoms.

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Treatment Options for Gastric Cancer

Treatment for gastric cancer depends on its stage, location, and hereditary factors. Common treatments include:

• Surgery: Removal of part or all of the stomach (gastrectomy).
• Chemotherapy and Radiation Therapy: Often used in combination to kill cancer cells or shrink tumors before surgery.
• Targeted Therapy: For advanced cases, drugs target specific cancer cell molecules.
• Immunotherapy: Boosts the body’s immune system to fight cancer.

Treatment strategies may differ for hereditary gastric cancer based on genetic mutations and individual risk factors.

FAQs on Hereditary Gastric Cancer

1. What are the chances of inheriting gastric cancer if my parent has it?

If your parent carries a mutation like CDH1, there is a 50% chance of inheriting it. Regular screenings and genetic counseling are advisable.

2. Can I develop gastric cancer even if it’s not in my family?

Yes, most gastric cancers are not hereditary and occur due to lifestyle or environmental factors.

3. What lifestyle changes can reduce my risk?

Adopting a healthy diet, avoiding smoking, limiting alcohol, and maintaining a healthy weight all help.

4. What is the role of H. pylori in gastric cancer, and is it hereditary?

H. pylori is a bacterial infection, not a hereditary condition. However, chronic infection significantly increases gastric cancer risk.

Conclusion

While most cases of gastric cancer arise from environmental or lifestyle factors, hereditary forms linked to genetic mutations, such as those in the CDH1 gene, account for a small but significant percentage. Understanding your family history and undergoing genetic screening can dramatically improve early detection and treatment outcomes.

Call-to-Action

Don’t wait—if gastric cancer runs in your family or you’re experiencing persistent stomach symptoms, consult your doctor. Schedule a genetic counseling session or screening today to take control of your health. Early diagnosis is your best defense!