Expression of CEACAM1 in Adenocarcinoma of the Lung: A Factor of Independent Prognostic Significance

To evaluate the prognostic relevance of CEACAM1 and sialyl Lewis X expression in adenocarcinomas of the lung. Paraffin wax sections of 93 patients with adenocarcinomas of the lung who underwent surgery between 1990 and 1995 were immunohistochemically investigated using monoclonal anti-CEACAM1 and sialyl Lewis X antibodies. The clinical course of all patients was followed up for a minimum of 5 years. Sixty-one tumors were classified as CEACAM1-positive, and 32 were classified as CEACAM1-negative. Patients with CEACAM1-positive tumors had a significantly poorer overall (P =.00025) and relapse-free (P =.00029) survival than those with CEACAM1-negative tumors. Only three patients did not express the sialyl Lewis X glycotope, whereas 90 tumors (97%) were sialyl Lewis X-positive. In multivariate Cox regression analysis, next to tumor stage and sex, only the expression of CEACAM1 was a significant independent prognostic factor for survival. Expression of CEACAM1 was an independent prognostic factor in our patient population and can be used to stratify patients with adenocarcinomas of the lung into low-risk and high-risk groups. In contrast, the expression of sialyl Lewis X was of no prognostic relevance because it was expressed in 97% of all investigated tumors, and most likely has no influence on the function of CEACAM1 in this tumor entity.