Gastric cancer

Gastric Cancer

Gastric cancer, also known as stomach cancer, is a malignant condition that arises from the lining of the stomach. It is a significant cause of cancer-related mortality worldwide, particularly in East Asia, Eastern Europe, and parts of Central and South America. This article provides an overview of the etiology, pathophysiology, clinical presentation, diagnosis, and treatment of gastric cancer.

Etiology

Gastric cancer is a multifactorial disease with several known risk factors:

• Helicobacter pylori infection: Chronic infection with the bacterium Helicobacter pylori is a major risk factor for gastric cancer. It causes chronic inflammation and can lead to atrophic gastritis and intestinal metaplasia, precursors to cancer.
• Dietary factors: High intake of smoked, salted, and pickled foods, as well as low consumption of fruits and vegetables, have been associated with increased risk.
• Genetic predisposition: Certain genetic mutations and hereditary syndromes, such as Hereditary Diffuse Gastric Cancer (HDGC), increase the risk of developing gastric cancer.
• Lifestyle factors: Smoking and alcohol consumption are also associated with an increased risk.

Pathophysiology

Gastric cancer typically develops through a series of precancerous changes in the gastric mucosa, often initiated by chronic inflammation. The most common histological type is adenocarcinoma, which can be further classified into intestinal and diffuse types based on the Lauren classification.

• Intestinal type: This type is more common in high-risk areas and is often associated with environmental factors and precancerous lesions such as intestinal metaplasia.
• Diffuse type: This type is less common, tends to occur in younger patients, and is often linked to genetic factors.

Clinical Presentation

Symptoms of gastric cancer are often nonspecific and may include:

• Early satiety
• Unintentional weight loss
• Abdominal pain or discomfort
• Nausea and vomiting
• Dysphagia (difficulty swallowing)
• Melena (black, tarry stools) or hematemesis (vomiting blood) in cases of bleeding

Diagnosis

The diagnosis of gastric cancer typically involves:

• Endoscopy: Upper gastrointestinal endoscopy with biopsy is the gold standard for diagnosis.
• Imaging: CT scans, endoscopic ultrasound, and PET scans may be used for staging and to assess the extent of disease.
• Histopathological examination: Biopsy samples are examined to confirm the diagnosis and determine the histological type.

Treatment

Treatment options for gastric cancer depend on the stage of the disease and may include:

• Surgery: Surgical resection, such as gastrectomy, is the primary treatment for localized gastric cancer.
• Chemotherapy: Often used in conjunction with surgery, chemotherapy can be administered preoperatively (neoadjuvant) or postoperatively (adjuvant).
• Radiation therapy: May be used in combination with chemotherapy for certain cases.
• Targeted therapy: Agents such as trastuzumab may be used for HER2-positive gastric cancer.

Prognosis

The prognosis of gastric cancer varies significantly based on the stage at diagnosis. Early-stage gastric cancer has a much better prognosis compared to advanced-stage disease. Regular screening and early detection are crucial in high-risk populations.

Also see

• Helicobacter pylori
• Hereditary Diffuse Gastric Cancer
• Gastrectomy
• Chemotherapy
• Endoscopy