Gastric cancers often seem to be benign ulcers, which are like pits in the stomach lining. Larger ulcers—more than 2 cm (û in.) in diameter—that have borders raised above the level of the surrounding stomach are more likely to be malignant .
 
Physical Examination 
There are few specific findings on a physical examination, and they generally indicate an advanced tumor .
• Enlarged lymph nodes above the left collarbone (supraclavicular node).
• Nodal masses around the rectum, inside the navel or in the abdomen (involving the ovary).
• Enlarged liver (hepatomegaly). 
• Increased fluid in the abdomen (ascites).

Blood and Other Tests 
• Test for hidden blood in the stools. 
• Complete blood count (CBC), which may indicate anemia from gastrointestinal bleeding.
• Serum chemistry profile to evaluate abnormal liver and bone chemistry enzymes , including tests for elevated
  levels of carcinoembryonic antigen (CEA) and levels of serum ferritin to indicate iron deficiency. The CEA test
  may not be covered by provincial health care plans.
• Analysis of gastric acid to detect achlorhydria.