Genetic and Enzymatic Evidence for Lewis Enzyme Expression in Lewis-negative Cancer Patients

It has been observed that the frequency of individuals with Lewis-negative erythrocytes is significantly higher in cancer patients than in healthy controls. In this study, 20 of the 66 (30.3%) patients with various cancers were typed as Lewis negative from their erythrocytes, while the same frequency in healthy controls was 11.1%. These 20 patients were divided into three groups based on the presence of Lewis blood group antigens and al-4-fucosyltransferase in their salivas: group 1,6 patients who had both Lewis antigens and al->4-fucosyltransferase activity; group II, 8 patients who had no Lewis antigens but possessed al4-fucosyltransferase activity; group III, 6 patients who had neither Lewis antigens nor al-+4-fucosyltransferase activity. The genotyping of Le genes by the PCR-RFLP methods, which have been developed and established by us recently, demonstrated that all 14 patients from groups I and II possess Le gene homozygously {LeILe) or heterozygously (Le/te), whereas all 6 patients from group HI were telle homozygotes. Only the 6 patients from group III were identified as the genuine Lewis-negative individuals. The immunohistochemical staining of the colorectal tumors also showed that the Lewis antigens could be detected on the tumors from groups I and II but not from group m.