Atlas of pathophysiology, 2 Edition

Part II - Disorders

Gastrointestinal Disorders

Gastric Cancer

Gastric carcinoma is common throughout the world and affects all races; however, mortality is highest in Japan, Iceland, Chile, and Austria. In the United States, the incidence has decreased by 50% during the past 25 years and the resulting death rate is one-third of what it was 30 years ago.

Age Alert

Incidence of gastric cancer is highest in men over age 40.

Causes

Unknown; commonly associated with atrophic gastritis

Predisposing factors

·   Tobacco smoke

·   Asbestos exposure

·   High alcohol intake

·   Intake of smoked, pickled, or salt-preserved foods

·   Type A blood

·   Helicobacter pylori infection (distal gastric cancer)

·   Family history of gastric cancer

Pathophysiology

According to gross appearance, gastric carcinoma can be classified as polypoid, ulcerating, ulcerating and infiltrating, or diffuse. The parts of the stomach affected by gastric carcinoma, listed in order of decreasing frequency, are the pylorus and antrum, the lesser curvature, the cardia, the body of the stomach, and the greater curvature. Gastric carcinoma infiltrates rapidly to regional lymph nodes, omentum, liver, and lungs.

Signs and symptoms

Early clues

·   Chronic dyspepsia, epigastric discomfort

Later clues

·   Weight loss, anorexia

·   Dysphagia, feeling of fullness after eating

·   Anemia, fatigue

·   Coffee-ground emesis

·   Bloody stools

Diagnostic test results

·   Barium X-rays of the GI tract with fluoroscopy show changes that suggest gastric cancer, including a tumor or filling defect in the outline of the stomach, loss of flexibility and distensibility; and abnormal gastric mucosa with or without ulceration.

·   Gastroscopy with fiber-optic endoscope visualizes gastric mucosa including presence of gastric lesions for biopsy.

·   Gastroscopic biopsy permits evaluation of gastric mucosal lesions.

·   Gastric acid stimulation test discloses whether the stomach secretes acid properly.

·   Complete blood count reveals anemia.

·   Liver function studies possibly elevated with metastatic spread of tumor to liver.

·   Radioimmunoassay reveals possibly elevated carcinoembryonic antigen.

Treatment

·   Excision of lesion with appropriate margins (possible in more than one-third of patients) by subtotal or total gastrectomy or gastrojejunostomy

·   Palliative surgery

·   Radiation therapy with chemotherapy for patients with unresectable or partially resectable disease

·   Antispasmodics, antacids for GI distress

·   Antiemetics

·   Opioid analgesics

·   Proton pump inhibitors or histamine-2 blockers

P.177

ADENOCARCINOMA OF THE STOMACH

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