RESUMO
Background: The ABO blood group antigens are present on the surface of red blood cells and various epithelial cells. As the majority of human cancers are derived from epithelial cells, changes in blood group antigens constitute an important aspect of human cancers. The aim of the study was to establish clinical usefulness of ABO blood group as a predisposing factor in early diagnosis and management of patients with oral precancerous lesions/conditions. Materials and Methods: The study sample consisted of 50 control and 50 oral precancer (25 leukoplakia and 25 Oral Submucous Fibrosis) confirmed by histopathologic examination. All samples were subjected to blood group testing and their prevalence was compared by Z-test using STATA version 8. Results: The "A" blood group was prevalent among the precancerous group. Significant differences on prevalences of blood groups were found (P < 0.05) between control versus leukoplakia and OSMF. Interestingly, 24% gutka chewers who had higher number of grades of dysplasia were falling in "A" blood group. Conclusion: Blood group type should be considered along with other risk factors to understand the individual patient's risk and further studies in larger samples with inclusion of Rh factor is needed to elucidate the relationship with ABO blood group types.