The expression of Ep-CAM (17-1A) in squamous cell cancers of the lung

Immunotherapy trials using monoclonal antibodies 323/A3 and 17-1A that reco gnize Ep-CAM, including trials focused on cancer of the lung currently are underway. Nevertheless, there have been few comprehensive evaluations of th e expression of Ep-CAM in specific types of neoplastic processes, including cancer of the lung. The current study of 60 human subjects: with squamous cell cancer (SCC) of the lung, selected at random, was undertaken (1) to ex amine the expression of Ep-CAM in SCC and associated uninvolved bronchial m ucosa, bronchial epithelial hyperplasia, and dysplasia, and (2) to correlat e the results with established prognostic indicators and survival of patien ts. In both the uninvolved bronchial mucosa and epithelial hyperplasia, the expression of Ep-CAM in luminal cells was significantly higher compared wi th its expression in the matched basal cells (P = .003, P < .0001, respecti vely). When Ep-CAM scores of basal and luminal cells present in uninvolved bronchial mucosa and epithelial hyperplasia were combined, we observed a st atistically significant stepwise increase in Ep-CAM expression from uninvol ved bronchial mucosa to epithelial hyperplasia to SCC, suggesting its invol vement in malignant transformation of SCC. The expression of Ep-CAM was sig nificantly higher in poorly to moderately differentiated SCC compared with well-differentiated SCC (P = .04). An increase in the expression of Ep-CAM with increasing size or local extent of the primary tumor approached statis tical significance (P = .09). The expression of EB-CAM increased significan tly with increasing involvement of regional lymph nodes (P = .02). Similarl y, the expression of Ep-CAM increased with the increasing TNM stages (P = . 04). Kaplan-Meier Survival analysis using the same categorizations showed t hat increasing tumor size, nodal status, and stage were significantly assoc iated with poor patient survival (P = .04, .01, .01, respectively). There w as, however, no statistically significant association between patient survi val and staining intensity of carcinomas for Ep-CAM. We conclude that expre ssion of Ep-CAM increased during the progression of SCC of the lung and, th erefore, may play a role in the carcinogenesis of this disease. HUM PATHOL 31:482-487. Copyright (C) 2000 by W.B. Saunders Company.