Individuals with the gene variant that results in A, B, or AB blood types appear to have a higher risk of developing pancreatic cancer than individuals with the gene variant that results in blood type O. These results were published in Nature Genetics.
Pancreatic cancer has one of the highest mortality rates of all cancers. It accounts for approximately 2% of all newly diagnosed cancers in the United States each year but 5% of all cancer deaths. Pancreatic cancer is often called a “silent killer” because its symptoms are usually not recognizable until it has advanced and spread outside the pancreas. As a result, the majority of pancreatic cancers are not diagnosed until they have reached advanced stages and are considered incurable. Research is ongoing to identify risk factors and genetic predisposition for this disease in the hopes of understanding how pancreatic cancer develops and how it might be prevented or detected at an early stage.
To explore how genetic variation influences risk of pancreatic risk, researchers conducted a genome-wide association study (GWAS). In this type of study, researchers assess common genetic variants known as single-nucleotide polymorphisms (SNPs) in people with and without disease.
The researchers first studied the genomes of 1,896 patients with pancreatic cancer and 1,939 people without pancreatic cancer in order to identify SNPs that were more common in patients with pancreatic cancer. They then verified their results in additional groups of people with and without pancreatic cancer.
The results suggested that several SNPs on chromosome 9 were linked with pancreatic cancer risk. The part of chromosome 9 that was involved contains the ABO gene (the gene that determines blood type). People who had gene variants for A, B, or AB blood types were more likely to develop pancreatic cancer than people who had the gene variant for blood type O. These results are consistent with previous studies that have suggested a relationship between blood type and risk of pancreatic cancer.
The results of this study suggest that variations in the ABO gene influence risk of pancreatic cancer. As researchers begin to understand the biological basis for this finding, it may lead to improvements in the prediction, diagnosis, and management of this disease.
 Amundadottir L, Kraft P, Stolzenberg-Solomon RZ et al. Genome-wide association study identifies variants in the ABO locus associated with susceptibility to pancreatic cancer. Nature Genetics [early online publication]. August 2, 2009.
 Wolpin BM, Chan AT, Hartge P, et al. ABO blood group and the risk of pancreatic cancer. Journal of the National Cancer Institute. 2009; 101:424-431.