Blood Type A and Gastric Cancer

Last Modified: September 17, 2006


Dear OncoLink "Ask The Experts,"

I have read that there may be an additional risk factor for gastric cancer for people with type A blood. If this is true, what if any preventive steps should be taken, and why is this true?


Weijing Sun, MD, Assistant Professor of Medicine at the University of Pennsylvania, the Director of Upper GI and Pancreatic-biliary-hepatic Cancer Group and the Associate Director of the GI Cancer Program, responds:

It has been noticed for many years that there is higher incidence of gastric cancer in blood type A population than in people with other blood types. It seems related more to the 'older type - distal gastric cancer' than 'proximal gastric cancer'. However, the mechanism / reason is unknown. Since the difference of blood types is based on the 'sugar' part of the glycoprotein on the cell membrane, it may not be the 'blood type' itself, rather some unknown molecule(s) adjacent to it.

I don't think there is any information about prevention from that prospect.