It has been observed that the frequency of individuals with Lewisnegative 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 α1→4-fucosyltransferase in their salivas: group I, 6 patients who had both Lewis antigens and α1→4-fucosyltransferase activity; group II, 8 patients who had no Lewis antigens but possessed α1→4-fucosyltransferase activity; group III, 6 patients who had neither Lewis antigens nor α1→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 (Le/Le) or heterozygously (Le/le), whereas all 6 patients from group III were le/le 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 III.
Supported in part by a Grant-in-Aid for Scientific Research (No. 01010001) from the Ministry of Education, Science, and Culture, Japan, and by a grant from Otsuka Parmaceutical Company, Japan.