Evaluation of expression of CD15 and sCD15 in non-small cell lung cancer

Changes in cell membrane carbohydrate antigens play an important role in me tastatic potential associated with carcinogenesis and in prognostic factors . We investigated immunohistochemically the expression of CD15 and sialyl C D15 (sCD15) in lung cancer tissue by using Leu-M1 antibody and MXKM-93 anti body, respectively, and then assessed the relationship between their expres sion and the patient outcome. Lung cancer tissue expression of CD15 was sig nificantly higher in adenocarcinoma (55.9%) and squamous cell carcinoma (44 .7%) than in small cell carcinoma (10%) (p=0.01, p=0.006). Expression of sC D15 was significantly higher in adenocarcinoma (52.9%) than in squamous cel l carcinoma (10.5%) or small cell carcinoma (10%) (p<0.0001, p=0.016). No a ssociation was found between CD15 expression and clinical stage, but sCD15 expression increased with clinical stage (stage I+II vs. III+IV: 16.7% vs. 39.6%; p=0.049). Expression of CD15 (1.5%) was significantly lower than exp ression of sCD15 (12.3%) in normal surrounding tissue. Examination of assoc iations with outcome in NSCLC revealed that expression of sCD15 in resected cases, and expression of CD15 in non-resected cases were significantly cor related with shortening of median survival time (p<0.05). When associations with prognostic factors were assessed by univariate analysis, expression o f sCD15 was found to be correlated with distant metastasis, and expression of CD15 with decrease in performance status (PS). In the multivariate analy sis by the Cox proportional hazard model, sCD15 and CD15 negativity contrib uted to longer survival lime after PS and clinical stage. The results of a combination assay of CD15 and sCD15 showed that expression of both carbohyd rate antigens significantly shortened survival time in both the resected an d non-resected group (log-rank rest, p<0.05). This combination assay also a ppeared to be extremely useful in predicting the outcome in all clinical st ages of NSCLC.