Gastric Cancer Overview

Study Notes

Carcinoma Stomach Incidence and Tumors

Gastric cancer incidence, particularly distal cancer, is on the decline; distribution shows distal tumors (40%) > middle tumors (30%) > proximal tumors (30%).
Increasing incidence of gastroesophageal (GE) junction tumors.
Malignant tumors comprise approximately 90% of all stomach tumors, predominantly gastric adenocarcinoma.
Common genetic abnormalities include p53 and COX-2 genes.
Tumor markers associated with gastric cancer: CEA, CA 19-9, CA-125, CA 72-4, and beta-HCG.

Clinical Features

Major symptoms include abdominal pain (62-91%) and weight loss (22-61%). Pain is typically constant, nonradiating, and unrelieved by eating.
Dysphagia is common in proximal tumors affecting the gastroesophageal junction; distal antral tumors may cause gastric outlet obstruction.
Extensive mural involvement by tumor (e.g., linitis plastica) can lead to stomach distensibility issues and early satiety.
Symptoms of advanced disease may include ascites, jaundice, or palpable masses.
Malignant spread may lead to fistula formation with the transverse colon and obstruction.
Notable physical findings: Virchow's lymph node (supraclavicular), Sister Mary Joseph's node (periumbilical), Irish nodes (left axilla), and Krukenberg's tumor (ovarian mass).
Paraneoplastic syndromes possible: thrombophlebitis (Trousseau's syndrome), neuropathies, nephrotic syndrome, and disseminated intravascular coagulation (DIC).

Lymph Node Metastasis

Risk of nodal metastases varies according to tumor origin and depth of gastric wall invasion.
Proximal stomach and GE junction tumors show greater likelihood of mediastinal and pericardial spread.
Tumors in the stomach body primarily metastasize to nodes along the greater and lesser curvature.
Distal stomach tumors tend to metastasize to periduodenal, peripancreatic, and porta hepatis nodes.

Diagnosis

Endoscopy with biopsy is the preferred method for diagnosing gastric cancer.
Endoscopic ultrasound (EUS) is the ideal choice for early gastric cancer staging.
Contrast-enhanced computed tomography (CECT) is best for preoperative staging.

Treatment by Site

Proximal-third: Extended gastrectomy including distal esophagus.
Middle-third: Total gastrectomy with D2 lymph node dissection.
Distal-third: Subtotal gastrectomy with D2 lymph node dissection for intestinal-type; total gastrectomy with D2 lymph node dissection for diffuse-type.

Recurrence

Most recurrences happen within the first three years.
Highest loco-regional failure rates occurring at anastomosis or stump (25%) followed by stomach bed (21%) and regional nodes.
Most common sites for metastasis: liver, lung, and bone.

Surveillance

Follow-up protocol includes history and physical examination every 4 months for the first year, then every 6 months for the following two years, transitioning to annual exams thereafter.

Prognosis

Prognostic factors to consider include stage at diagnosis, histological type, and treatment response.

Description

This quiz covers key aspects of gastric cancer, including its incidence, distribution, and the types of tumors prevalent in the stomach. You'll also learn about the most common genetic abnormalities and tumor markers associated with gastric adenocarcinoma. Test your knowledge on this significant health issue.