Association Between ABO Polymorphism and Gastric/Colorectal Cancers

The ABO blood group system was discovered by the Austrian pathologist Karl Landsteiner in 1901, who classified the blood groups based on the presence of A and B antigens on the surface of red blood cells after noting patterns of agglutination during blood transfusion. Since the discovery of the ABO blood group system , several studies investigating the relationship between the ABO blood group system and various diseases have been conducted , cancer included . First association between ABO blood group and cancer risk was reported in 1953 in The English patients with gastric cancer. Gastric cancer is one of the most common malignant tumors of the digestive system , worldwide, gastric cancer is still the fourth most common cancer and the second most common cause of cancer death . The development of gastric cancer is caused by the interaction of genetic and environmental factors , ABO blood grouping is one of the most stable genetic factors. This association is also observed with other gastrointestinal malignancies, including colorectal cancer which considered the third common cancer in both women and men and responsible for approximately 10% of all cancers, and the third most common cause of cancer related mortality for men and fourth for women . The ABO is also the first blood group system defined at the gene level . SNP is a single nucleotide polymorphism, is a germ line substitution of a single nucleotide at a specific position in the genome that is present in a sufficiently large fraction of considered population , SNP may act as biological markers, as they can relate to the genes that are associated with various complex diseases as heart diseases, diabetes, cancer … etc. In previous studies , significant association between ABO gene SNP (rs8176746) , H. Pylori infection, gastric and pancreatic cancer were found , as they observed that this gene SNP was associated with decreased risk of these disorders.