March 10 (HealthDay News) --- People with type O blood have a much lower risk of developing pancreatic cancer, a finding that might help explain the origins of the often fatal disease.
The study, by researchers at the Dana-Farber Cancer Institute in Boston, confirms a previously suggested tie between blood type and the disease, which is diagnosed in about 40,000 people each year in the United States.
The study found that the chances of developing pancreatic cancer were greater for people with a blood type other than O: 32 percent higher for those with type A blood, 51 percent greater for type AB and 72 percent higher for type B .
However, because only a little more than 1 percent of the general population is at risk for the disease, the researchers said that blood type would not serve as a helpful screening method in the future.
"Except for several rare familial syndromes, the genetic factors that raise or lower an individual's risk for pancreatic cancer are largely unknown," the study's lead author, Dr. Brian Wolpin, said in a news release from the cancer institute.
"The association between blood type and pancreatic cancer risk provides a new avenue for getting at the biological mechanisms that underlie the disease," he said. "Understanding the biology will put us in a better position to intervene so the cancer doesn't develop or progress."
Glycoproteins, compounds of sugar and protein found on the surface of red blood cells and other cells, including those in the pancreas, help define the four major blood types. A gene called ABO helps put these glycoproteins together by arranging sugar molecules on a protein "backbone" called the H antigen. In people with type O blood, the antigen has no sugars attached to it.
Previous studies have found that normal pancreas cells have blood-type antigen patterns that differ from those in pancreatic tumor cells, leading to speculation that the ABO gene might have a role in determining whether cells become cancerous.
The authors, whose study was published online in the Journal of the National Cancer Institute, wrote that their findings do not necessarily prove a direct link between blood-type antigens and pancreatic cancer development, but they may show that the ABO gene serves as a marker for other genes more directly involved in cancer development.
SOURCE: Dana-Farber Cancer Institute, news release, March 10, 2009