Abstract
The incidence of colorectal carcinoma was compared with the incidence of ABO and Lewis blood groups. The raw data showed the known overrepresentation of the Le(a–b–) phenotype, but also suggested an association of colorectal carcinoma with the Le(a–b+) phenotype in group O individuals. When the data were adjusted by taking into account the known loss of Lewis antigens by Lewis-positive patients, this association could be shown to be statistically significant. These results may indicate involvement of the secretory H antigen in colorectal carcinoma. Immunohematology 1993;9:101.