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Stomach Cancer (Gastric Carcinoma) – Comprehensive Medical Guide

Overview

Stomach cancer, also called gastric carcinoma, is a malignant growth that originates in the lining of the stomach. It most often begins as an adenocarcinoma, a cancer that forms from glandular cells. While the incidence of stomach cancer has declined in many high‑income countries, it remains one of the leading causes of cancer‑related deaths worldwide.

• Global prevalence: Approximately 1.1 million new cases and 770,000 deaths were reported in 2020, making it the 5<sup>th</sup> most common cancer and the 4<sup>th</sup> leading cause of cancer mortality worldwide (World Health Organization, 2023).
• Geographic variation: Highest rates are observed in East Asia (Japan, South Korea, China), Eastern Europe, and parts of South America. In the United States, the age‑adjusted incidence is about 7 per 100,000 people per year.
• Typical age: Median age at diagnosis is 68 years; cases before age 40 are rare and often linked to hereditary syndromes.

Symptoms

Early gastric cancer often produces no symptoms, which contributes to delayed diagnosis. When symptoms appear, they may be vague or overlap with many benign gastrointestinal disorders.

Common Symptoms

• Persistent indigestion or heartburn – a feeling of burning or discomfort after meals.
• Upper abdominal pain or fullness – may feel like a bloated sensation even after a small meal.
• Unexplained weight loss – loss of ≥ 10 % body weight over a short period without trying.
• Loss of appetite – reduced desire to eat, sometimes called early satiety.
• Nausea or vomiting – can be occasional or frequent; vomiting may contain blood (hematemesis) in advanced disease.
• Vomiting of coffee‑ground‑like material – indicates digested blood in the stomach.
• Dark or tarry stools (melena) – sign of upper gastrointestinal bleeding.

Less Common but Important Signs

• Difficulty swallowing (dysphagia) – usually when the tumor obstructs the gastro‑esophageal junction.
• Persistent hiccups – may result from irritation of the diaphragm by a large tumor.
• Anemia‑related fatigue – iron‑deficiency anemia due to chronic bleeding.
• Jaundice – rare, occurs if cancer spreads to the liver or bile ducts.

Causes and Risk Factors

Most gastric cancers develop over many years through a series of precancerous changes. The exact cause is multifactorial.

Major Risk Factors

• Helicobacter pylori infection: Chronic infection causes gastritis and intestinal metaplasia; it is responsible for ~ 60‑70 % of cases (NIH, 2022).
• Dietary habits: High intake of smoked, salted, or pickled foods; low consumption of fresh fruits and vegetables; and excess processed meat increase risk.
• Smoking: Current smokers have a 1.5‑ to 2‑fold higher risk.
• Alcohol abuse: Heavy alcohol use may potentiate the effect of H. pylori.
• Family history and genetics: First‑degree relatives with gastric cancer double the risk; hereditary diffuse gastric cancer (CDH1 gene mutation) confers a lifetime risk > 80 %.
• Pre‑existing gastric conditions: Chronic atrophic gastritis, intestinal metaplasia, pernicious anemia, and gastric polyps.
• Age & sex: Incidence rises sharply after age 50; males are 2‑3 times more likely to develop the disease.
• Occupational exposure: Workers exposed to asbestos, rubber, or nickel may have modestly increased risk.

Protective Factors

• Regular consumption of fresh fruits, vegetables, and foods rich in antioxidants (vitamin C, β‑carotene).
• Use of antibiotics or probiotic therapy that eradicate H. pylori.
• Maintaining a healthy body weight and limiting processed red meat.

Diagnosis

When gastric cancer is suspected, a systematic approach is used to confirm the diagnosis, stage the disease, and plan treatment.

Initial Evaluation

• Medical history and physical exam: Focus on gastrointestinal symptoms, weight loss, family history, and risk factors.
• Laboratory tests: Complete blood count (CBC) for anemia, liver function tests, and serum electrolytes. Tumor markers such as CEA and CA 19‑9 may be ordered, though they are not diagnostic.

Imaging & Endoscopic Studies

• Upper endoscopy (esophagogastroduodenoscopy, EGD): Gold‑standard for visualization and biopsy. Allows targeted tissue sampling and assessment of mucosal appearance.
• Endoscopic ultrasound (EUS): Determines depth of tumor invasion (T stage) and evaluates regional lymph nodes.
• Contrast‑enhanced CT scan of the abdomen/pelvis: Staging tool to detect local spread, liver metastases, and ascites.
• Positron emission tomography (PET‑CT): Useful for identifying distant metastatic disease not seen on CT.
• Upper gastrointestinal (UGI) series (barium swallow): Rarely used now, but can demonstrate obstruction or ulceration.

Pathology

Biopsy specimens are examined by a gastrointestinal pathologist. The Lauren classification distinguishes two major histologic types:

• Intestinal type: Often linked to environmental factors, forms gland‑like structures.
• Diffuse type: Associated with CDH1 mutation, characterized by scattered signet‑ring cells.

Immunohistochemistry and molecular testing (e.g., HER2 overexpression, microsatellite instability [MSI], PD‑L1) guide targeted therapy.

Treatment Options

Treatment is individualized based on tumor stage, location, patient’s performance status, and molecular profile.

Curative Intent (Early‑Stage Disease)

• Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD): For confined lesions ≤ 2 cm with no lymphovascular invasion.
• Surgical resection:
  • Subtotal (distal) gastrectomy – removal of the lower two‑thirds of the stomach, common for tumors in the antrum.
  • Total gastrectomy – removal of the entire stomach, indicated for proximal or diffuse tumors.
  • Reconstruction usually performed with Roux‑en‑Y esophagojejunostomy.
• Adjuvant chemotherapy: Typically a fluoropyrimidine (5‑FU or capecitabine) combined with platinum (oxaliplatin) for 6 months (e.g., XELOX regimen).
• Adjuvant chemoradiotherapy: Used in selected cases, especially after D2 lymphadenectomy with positive margins or high‑risk pathology (INT-0116 trial, McGill University).

Advanced / Metastatic Disease

• Systemic chemotherapy: Combination regimens such as FOLFOX (5‑FU, leucovorin, oxaliplatin) or DCF (docetaxel, cisplatin, 5‑FU) are standard.
• Targeted therapy:
  • Trastuzumab for HER2‑positive tumors (ToGA trial).
  • Ramucirumab (VEGFR‑2 antagonist) alone or with paclitaxel.
• Immunotherapy: PD‑1 inhibitors (nivolumab, pembrolizumab) approved for tumors with high MSI or PD‑L1 CPS ≥ 10.
• Palliative surgery: May be performed to relieve obstruction, bleeding, or perforation.
• Radiation therapy: Primarily used for symptom control or in combination with chemotherapy for unresectable disease.

Lifestyle & Supportive Measures

• Nutrition counseling – high‑protein, low‑sugar diet; consider enteral feeding if oral intake is limited.
• Management of anemia – iron supplementation or blood transfusions.
• Psychosocial support – counseling, support groups, and palliative‑care referral when appropriate.

Living with Stomach Cancer (Gastric Carcinoma)

Adjusting to life after diagnosis involves practical daily strategies.

Nutrition

• Eat small, frequent meals; chew food thoroughly.
• Avoid extremely hot, spicy, or acidic foods that can irritate the stomach.
• Include protein‑rich foods (lean meats, eggs, Greek yogurt) to counteract muscle loss.
• Work with a registered dietitian experienced in oncology.

Managing Side Effects

• Nausea/vomiting: Use prescribed anti‑emetics (e.g., ondansetron) before meals.
• Diarrhea: Stay hydrated; consider loperamide as directed.
• Neuropathy from oxaliplatin: Limit exposure to cold temperatures; report tingling early.
• Fatigue: Prioritize rest, gentle exercise (walking, yoga) and maintain a regular sleep schedule.

Follow‑up Care

• Routine surveillance endoscopy every 1‑2 years for high‑risk patients.
• CT imaging every 3‑6 months during the first two years after curative treatment.
• Vaccinations: consider hepatitis B and pneumococcal vaccines if immunosuppressed.

Emotional & Practical Support

• Join patient advocacy groups (e.g., G+ Cancer Alliance).
• Explore financial counseling for treatment costs.
• Maintain open communication with your oncology team about goals of care.

Prevention

Because many risk factors are modifiable, preventive measures can substantially lower incidence.

• Eradicate Helicobacter pylori: Testing and appropriate antibiotic therapy for infected individuals reduces risk by up to 40 % (CDC, 2023).
• Adopt a cancer‑protective diet: Increase fresh fruit, cruciferous vegetables, and whole grains; limit smoked, salted, or nitrite‑rich foods.
• No tobacco: Quit smoking; seek counseling or nicotine replacement therapy.
• Limit alcohol: No more than 2 drinks/day for men, 1 for women.
• Maintain healthy weight: Obesity is linked to increased gastric cardia cancer.
• Regular medical check‑ups: Individuals with a strong family history or known CDH1 mutation should undergo genetic counseling and periodic endoscopic screening.

Complications

If untreated or advanced, gastric cancer can lead to serious, sometimes life‑threatening problems.

• Obstruction: Tumor blockage causes severe vomiting, inability to eat, and weight loss.
• Bleeding: Chronic ulceration may lead to anemia or acute hemorrhage (hematemesis, melena).
• Perforation: A full‑thickness rupture can cause peritonitis, requiring emergency surgery.
• Metastasis: Common sites include liver, peritoneum, lungs, and bones, causing organ‑specific symptoms.
• Cachexia: Cancer‑related metabolic wasting resulting in severe muscle loss and fatigue.
• Paraneoplastic syndromes: Rare hormonal or neurologic disturbances associated with tumor secretion.

When to Seek Emergency Care

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Sources: Mayo Clinic, CDC, National Institutes of Health, World Health Organization, Cleveland Clinic, NCCN Guidelines (2024), ToGA Trial (Lancet Oncology 2021), INT‑0116 Study (NEJM 2001).

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