CD40 and Bcl2 expression in squamous cell carcinoma of the lung: Correlation with apoptosis, survival, and other clinicopathological factors

CD40 is a cell surface receptor which, when ligated, modulates apoptosis in some cell types, perhaps via activation of the expression of members of th e Bcl2 gene family. This study sought to determine whether expression of CD 40 in a series of 134 squamous cell carcinomas (SCCs) of the lung was relat ed to apoptosis or clinical parameters, either alone or in connection with Bcl2 expression. Sections of SCCs were stained for CD40 and Bcl2 by immunoh istochemical techniques. An index was determined for these two markers by c ounting stained and unstained malignant cells under high power. Sections we re also stained by haematoxylin and eosin for determination of the apoptoti c index by counting apoptotic bodies. About 40 per cent of SCCs expressed C D40 in at least some of the malignant cells, with about 10 per cent essenti ally uniformly stained. Similar proportions expressed Bcl2, with a tendency for expression to be mutually exclusive. Apoptosis did not correlate with CD40 expression, nor was there evidence of a co-operative or an antagonisti c effect with Bcl2. Bcl2 expression, on the other hand, correlated signific antly with the apoptosis score. CD40 expression showed no significant relat ionship with survival or any other clinicopathological parameter except plo idy. Bcl2 expression, however, correlated with longer survival. It is concl uded that CD40 expression in SCC of the lung does not by itself relate to a poptosis, nor is it a useful indicator of prognosis. Copyright (C) 1999 Joh n Wiley & Sons, Ltd.