Gastric Carcinoma is the second most common fatal malignancy (after lung cancer) in the world. There are unexplained wide international variations, being especially common in Japan, China and parts of South America.
Etiology of Gastric carcinoma
Risk factors of Gastric Carcinoma include
Age: carcinoma of stomach occurs between ages of 40 to 60 years and the average age is 38 years.
Dietary factors: nitrosamides and nitrosamines derived from nitrates used as preservatives in prepared food stuffs. High intake of starch may alter the pattern of gastric secretion and predisposes to cancer of stomach. Smoked and salted meats, rice dusted with asbestos containing talc, low green vegetables predispose to gastric carcinoma. Tobacco smoke, tobacco juice and consumption of alcohol have carcinogenic effect on gastric cancer.
Genetic predisposition: inherited mutation of E-cadherin
Precancerous lesions: chronic gastritis with intestinal metaplasia and H. pylori infection
H. Pylori: chronic gastritis associated with H.pylori infection remains major risk factor for gastric atrophy, intestinal metaplasia and ultimately dysplasia and gastric carcinoma.
Classification of Gastric Carcinoma
Early gastric carcinoma is defined as a lesion confined to the mucosa and submucosa, regardless of the presence or absence of perigastric lymph node metastases.
Advanced gastric carcinoma is a neoplasm that has extended below the submucosa into the muscular wall and perhaps spread more widely.
Gross types of early gastric carcinoma on the basis of growth pattern
Gross types of advanced gastric carcinoma on the basis of growth pattern
Metastasis of Gastric Carcinoma
Direct: extension to esophagus, duodenum, pancreas, and colon by growth along with submucosa and muscularis. It also spread to diaphragm and abdominal wall by direct continuity and by infiltration.
Lymphatic: to regional (perigastric) lymph nodes; supraclavicular lymph nodes (through the thoracic duct)- Virchow’s nodes
Vascular: liver, lungs…
Transcoelomic: bilateral involvement of the ovaries
Diagnosis of Gastric Carcinoma
Histamine fast achlorhydria
Cytology of gastric secretion
Carcino embryonic antigen is increased in the blood in one fourth of patients with advanced gastric carcinoma