Stomach cancer also called gastric cancer occurs when cells in the lining of the stomach begin to grow in an uncontrolled way and form a tumour.

Overview

Stomach cancer also called gastric cancer occurs when cells in the lining of the stomach begin to grow in an uncontrolled way and form a tumour.

Most stomach cancers grow slowly over many years and because symptoms are often vague in early stages, the cancer is usually diagnosed when it has already grown or spread, making awareness and early medical attention especially important.

How common is stomach cancer?

• Stomach cancer is the 5th most commonly diagnosed cancer and the 5th leading cause of cancer-related death worldwide
• In 2022, approximately 968,000 new cases were diagnosed globally, with close to 660,000 deaths
• In India, stomach cancer accounts for 6.3% of all cancer cases

Who is commonly affected?

Stomach cancer is more common in:

• Men — it affects men almost twice as often as women
• People over the age of 50, with the highest rates seen in those aged 60–80
• Those infected with a bacteria called Helicobacter pylori
• People with a close family member who has had stomach cancer
• Those who smoke, drink alcohol regularly or eat a diet high in salt-preserved or smoked foods

What causes stomach cancer?

Though the exact cause of stomach cancer is unknown, there are several factors are known to increase the risk of developing it.

Risk factors include:

• Infection with Helicobacter pylori bacteria — the single most important known risk factor as it may severely inflame the stomach
• Age over 50 — risk rises sharply with age
• Being male — men are approximately twice as likely to develop stomach cancer
• Family history — having a parent or sibling with stomach cancer increases risk
• Inherited conditions such as hereditary diffuse gastric cancer (a rare gene mutation) or other conditions
• Previous stomach surgery or a condition called pernicious anaemia (which reduces stomach acid)
• Diet high in salty, smoked, or preserved foods (e.g. pickled vegetables, salted fish)
• Low intake of fresh fruits and vegetables
• Smoking — smokers are up to twice as likely to develop stomach cancer compared to non-smokers
• Heavy alcohol consumption
• Obesity, particularly for cancers of the upper stomach (near the food pipe junction)

Symptoms of stomach cancer

• Persistent indigestion or heartburn that does not improve with usual medicines
• Feeling full very quickly after eating even a small amount
• Loss of appetite, especially for meat
• Unexplained weight loss
• Nausea or vomiting
• Pain or discomfort in the upper abdomen (tummy area)
• Feeling bloated after meals
• Difficulty swallowing (food feeling stuck going down)

Warning signs of a serious condition

• Vomiting blood or passing black, tarry stools (which can mean bleeding in the stomach)
• A lump that can be felt in the upper abdomen
• Severe or sudden onset of abdominal pain
• Yellowing of the skin or whites of the eyes (jaundice)
• Persistent tiredness or shortness of breath (possible signs of anaemia from blood loss)

Diagnosis and Investigations

Routine clinical evaluation

• Gastroscopy (upper endoscopy): A thin, flexible tube with a tiny camera is passed through the mouth and down into the stomach under mild sedation. The specialist looks for any unusual growths or abnormal areas in the stomach lining.
• Biopsy: A small tissue samples are taken from any abnormal areas and sent to a laboratory to check for cancer cells. This is the only definitive way to confirm a diagnosis.

Further tests

• CT scan (Computed Tomography): Detailed X-ray that helps determine whether the cancer has spread to nearby lymph nodes or other organs such as the liver
• Endoscopic ultrasound (EUS): Combines the endoscope with an ultrasound probe to measure how deeply the tumour has grown into the stomach wall and whether nearby lymph nodes are affected
• PET scan: Specialised scan that shows areas of increased activity in the body, helping to detect spread of cancer to distant sites
• Laparoscopy: A small keyhole surgical procedure under general anaesthetic that lets the surgeon look directly inside the abdomen for any spread of cancer not visible on scans

Understanding staging

After all tests are complete, the cancer is given a stage (Stage I to IV) that describes how large it is and how far it has spread. Stage I means the cancer is small and contained; Stage IV means it has spread to distant parts of the body. Staging helps your medical team decide the most suitable treatment.

What to expect:

• A gastroscopy takes around 10–15 minutes and is not painful but it may be little uncomfortable
• You will be offered a local anaesthetic throat spray or sedation to help you relax
• Biopsy results are usually available within 2 weeks
• Your specialist will explain all findings and discuss treatment options with you

Treatment options

Treatment depends on the stage of the cancer and includes surgeons, cancer specialists, and other health professionals.

Surgery

• The main treatment for stomach cancer that has not spread beyond the stomach
• Partial gastrectomy: Removal of the part of the stomach containing the tumour
• Total gastrectomy: Removal of the entire stomach, with the food pipe connected directly to the small intestine
• For very early cancers confined to the stomach lining, endoscopic surgery (removing the cancer through the endoscope without opening the abdomen) may be possible

Chemotherapy

• Uses medicines to destroy cancer cells. Often given before surgery (to shrink the tumour) and after surgery (to reduce the risk of the cancer returning)
• Can also be used as the main treatment when surgery is not possible, to slow the cancer and relieve symptoms

Radiotherapy

• Uses high-energy X-ray beams targeted at the cancer to destroy cancer cells
• Not commonly used alone for stomach cancer, but may be given alongside chemotherapy after surgery or to control symptoms such as bleeding

Targeted therapy and immunotherapy

• Trastuzumab (Herceptin): Drug targeting advanced stomach cancers that test positive for a protein called HER2
• Immunotherapy drugs such as nivolumab or pembrolizumab may be used in certain advanced cases

When is more aggressive treatment needed?

• Surgery combined with chemotherapy is recommended when the cancer is localised or has spread only to nearby lymph nodes
• When the cancer has spread widely, treatment focuses on controlling the disease and improving quality of life
• All treatment decisions are made jointly with you, taking your preferences and overall health into account

Lifestyle and prevention

Recommended diet

• Plenty of fresh fruits and vegetables daily
• Whole grains (brown rice, oats, whole wheat bread)
• Lean proteins (fish, pulses, legumes, low-fat dairy)
• Reduce intake of salt, pickled, smoked and processed foods
• Limit red meat and avoid processed meats where possible

Exercise

• At least 150 minutes per week of moderate physical activity (e.g. walking, swimming, cycling)
• Even light daily activity helps recovery and improves wellbeing
• Discuss with your doctor before starting or changing any exercise routine after treatment

Long-term care

• Regular follow-up: Monitoring is essential after treatment
• Take prescribed medicines on time and report any new or worsening symptoms promptly
• If H. pylori is detected, complete the full course of antibiotic treatment as instructed
• Stop smoking and limit alcohol consumption
• Seek nutritional support: Eating can be challenging after stomach surgery

When to contact a doctor?

• Persistent indigestion, heartburn or difficulty swallowing that does not improve
• Unexplained weight loss or loss of appetite lasting more than a few weeks
• Blood in vomit or black/tarry stools, immediately seek medical attention
• Any new pain, swelling or symptoms following treatment

Myths and facts

Myth 1: Stomach cancer always causes obvious symptoms early on

Fact: Most people with early stomach cancer have no symptoms at all, or have very mild symptoms such as indigestion, which is why it is often diagnosed at a later stage.

Myth 2: H. pylori infection always leads to cancer

Fact: No, it is a significant risk factor and should be treated with antibiotics if detected, as this can substantially lower the risk.

Myth 3: Stomach cancer cannot be treated

Fact: When detected early, stomach cancer is often treatable and can be cured with surgery, sometimes combined with chemotherapy. Even in advanced cases, treatments can help control the disease and maintain quality of life.

frequently asked questions (FAQs)