Lewisy (Ley), also designated CD174,
represents a carbohydrate blood group antigen which is
strongly expressed in neoplastic gastrointestinal tissues.
Previous reports indicated an association between Ley
expression and apoptosis. Therefore, we tried to
elucidate its clinicopathological relevance in a series of
160 gastric and 215 colorectal carcinomas by
immunohistochemical detection of Ley and visualization
of apoptotic cells applying the in-situ-end labelling
(ISEL) method, followed by semiquantitative scoring of
the specimens. In both gastric as well as colorectal
carcinomas, between 40 and 50% of the cases were Ley
reactive. Signet-ring cell carcinomas of the stomach
exhibited a significantly stronger Ley expression
compared to other tumor types. In colorectal cancers,
Ley was associated with increased tumor staging,
showing the strongest positivity in stage IV. Further
correlations with clinicopathological variables or
prognosis were not observed. On the other hand, the
amount of apoptotic cells was significantly reduced in
mucinous adenocarcinomas of the colorectum compared
to non-mucinous carcinomas. Scoring of apoptotic cells
did not result in any other clinicopathologically relevant
correlations. In addition, a significant association
between Ley antigen expression and apoptosis score
could not be established. Therefore, the hypothesis of a
functional relationship between these two aspects of
gastrointestinal tumor biology is not confirmed by our
data