What is Stomach Cancer?
Ever wondered what exactly “stomach cancer” means? In simple terms, stomach cancer—also known as gastric cancer—happens when cells in the stomach lining grow uncontrollably and form a tumor. It’s not just one disease, but rather several types depending on which part of the stomach is affected and how the cells behave.
Globally, stomach cancer is the fifth most common cancer and the fourth leading cause of cancer-related death. It’s more prevalent in East Asia, Eastern Europe, and parts of South America, but it can affect anyone, anywhere.
How Does Stomach Cancer Occur?
Let’s break this down. Imagine your stomach as a muscular bag that churns food. Its lining is coated with mucus to protect it from strong digestive acids. But when something damages this lining—such as bacteria, chronic inflammation, or lifestyle factors—mutations can begin.
These mutations change normal cells into cancerous ones, often starting in the innermost layer (the mucosa). Over time, cancer can grow deeper into the stomach wall and even spread to other parts of the body. Think of it like a leak in a water pipe that slowly corrodes the entire system.
What Are the Causes of Stomach Cancer?
So what triggers these changes? Stomach cancer doesn’t just appear out of nowhere—it builds up over time. Here are some of the main culprits:
- Helicobacter pylori infection: This common stomach bacteria is linked to 60–70% of stomach cancer cases. It causes chronic inflammation that can damage the stomach lining.
- Diet: High intake of salted, smoked, or pickled foods increases risk.
- Smoking: Smokers are twice as likely to develop stomach cancer compared to non-smokers.
- Genetics: Inherited mutations like hereditary diffuse gastric cancer (HDGC) can play a role, although this is rare.
Who Is at Risk?
Stomach cancer doesn’t play favourites—but some people are more likely to get it. Risk factors include:
- Age: Most cases occur in people over 50.
- Gender: Men are more likely than women to be affected.
- Family history of stomach cancer.
- H. pylori infection, especially long-standing.
- Smoking and alcohol use
- Obesity
- Diet low in fruits and vegetables
- Previous stomach surgery or chronic gastritis
- Pernicious anemia
Of these, H. pylori infection and dietary habits are among the most significant modifiable risks.
What Are the Symptoms of Stomach Cancer?
One of the challenges with stomach cancer is that early symptoms can be vague—often mistaken for common stomach issues. But as the disease progresses, certain signs become more noticeable:
- Persistent indigestion or heartburn
- Feeling full after eating small amounts
- Bloating after meals
- Stomach pain or discomfort
- Unexplained weight loss
- Vomiting (sometimes with blood)
- Black or bloody stools
- Fatigue or anemia
Why do these symptoms occur? As the tumor grows, it interferes with normal digestion and may even bleed or block parts of the stomach.
Differential Diagnosis: What Else Could It Be?
Since many stomach cancer symptoms are non-specific, doctors often consider other possibilities before confirming the diagnosis. These may include:
- Peptic ulcers
- Gastroesophageal reflux disease (GERD)
- Gastritis
- Functional dyspepsia
- Pancreatic or esophageal cancer
That’s why thorough testing is essential. You wouldn’t want to mislabel a stomach ulcer as cancer—or miss a serious condition thinking it’s just reflux.
How Is Stomach Cancer Diagnosed?
The gold standard for diagnosis? Upper endoscopy (gastroscopy) with biopsy.
Here’s how it works: A thin, flexible tube with a camera is inserted through your mouth into the stomach. The doctor can view the stomach lining and take small tissue samples (biopsies) for lab testing. It’s quick, usually painless (with sedation), and highly accurate.
Additional investigations may include:
- CT scan or PET scan – to check for spread (staging)
- Endoscopic ultrasound (EUS) – to evaluate depth and nearby nodes
- Blood tests – to detect anemia or tumor markers like CEA or CA 19-9
- Laparoscopy – sometimes done before surgery to check for hidden spread
Types of Stomach Cancer
Not all stomach cancers are the same. The most common type is:
- Adenocarcinoma (about 90–95% of cases) – begins in mucus-producing cells
Less common types include:
- Lymphoma – cancer of immune cells in the stomach wall
- Gastrointestinal stromal tumor (GIST) – rare tumor of the muscle layer
- Neuroendocrine tumors – slow-growing but can be aggressive
Knowing the type helps guide treatment decisions.
How Is Stomach Cancer Treated?
Treatment depends on the stage and location of the cancer, as well as the person’s overall health. Often, a combination approach is best. Here’s a breakdown:
1. Surgery (Gold Standard for Curative Treatment)
If the cancer is caught early and hasn’t spread, surgery offers the best chance of a cure. The two main procedures are:
- Subtotal (partial) gastrectomy – part of the stomach is removed
- Total gastrectomy – the entire stomach is removed, and the esophagus is connected to the small intestine
Nearby lymph nodes are also removed during surgery.
2. Chemotherapy
Used before surgery (neoadjuvant) to shrink tumors or after surgery (adjuvant) to kill remaining cells. Sometimes used as the main treatment if surgery isn’t possible.
Common drugs:
- Cisplatin
- Fluorouracil (5-FU)
- Capecitabine
- Oxaliplatin
3. Radiation Therapy
May be combined with chemotherapy or used when surgery isn’t an option. Helps with symptom relief too (like pain or bleeding).
4. Targeted Therapy
For advanced cases, drugs like trastuzumab (Herceptin) can be used if the cancer has HER2 overexpression.
5. Immunotherapy
Drugs like nivolumab or pembrolizumab help the body’s immune system fight cancer cells—especially in advanced or recurrent cases.
6. Supportive/Palliative Care
Even when a cure isn’t possible, treatment can help relieve symptoms and improve quality of life—nutrition support, pain relief, and psychological support all matter.
Can Stomach Cancer Be Prevented?
While you can’t change your genetics, there are steps you can take to reduce your risk:
- Get tested and treated for H. pylori
- Eat a healthy diet rich in fruits and vegetables
- Cut back on salty and smoked foods
- Avoid smoking and limit alcohol
- Maintain a healthy weight
- Have regular check-ups if you’re high-risk
Living with Stomach Cancer: What to Expect
A diagnosis of stomach cancer can feel overwhelming. But you’re not alone. With advances in treatment and earlier detection, more people are surviving longer and living better lives.
It helps to:
- Build a support team (doctors, nurses, counselors, family)
- Understand your treatment options
- Focus on nutrition and self-care
- Speak up about any symptoms or side effects
When to See a Doctor
Still ignoring that bloated feeling or unexplained fatigue? If you notice persistent stomach discomfort, weight loss, or blood in your stool—get checked. The earlier it’s caught, the better the outcome.
References
- Stomach Cancer – Overview, American Cancer Society. https://www.cancer.org/cancer/stomach-cancer.html
- Gastric Cancer Treatment (PDQ®)–Patient Version, National Cancer Institute. https://www.cancer.gov/types/stomach/patient/stomach-treatment-pdq
- Gastric Cancer: Epidemiology and Risk Factors, World Journal of Gastroenterology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7123023/
- Clinical Practice Guidelines for Gastric Cancer, ESMO. https://www.esmo.org/guidelines/gastrointestinal-cancers/gastric-cancer
- Helicobacter pylori and Cancer, World Health Organization. https://www.iarc.who.int/wp-content/uploads/2018/07/pr157_E.pdf