Aim: The cell adhesion molecule L1 (L1-CAM) is overexpressed in a variety of human cancers and is correlated to bad prognosis. So far only lung cancer cell lines have been tested for L1-CAM expression. Therefore, we aimed to evaluate the diagnostic and prognostic value of this molecule in non-small cell lung cancer (NSCLC) tissue.

Methods: We studied tumours of 509 surgically treated NSCLC patients, assembled on a tissue microarray. The cell membrane protein expression of L1-CAM was immunohistochemically determined and semi-quantitatively scored by two pathologists. Correlations of protein expression with clinico-pathologic parameters were calculated by chi-squared tests, overall survival by the Kaplan-Meier method.

Results: L1-CAM protein was overexpressed in 8.7% of the cases. Histological subtype analysis showed that of squamous cell carcinomas 12.9%, of adenosquamous carcinomas 33.3% and of adenocarcinomas 6.7% expressed high membranous L1-CAM. High L1-CAM protein expression was significantly correlated with higher grade, larger tumour size, higher stage and vessel infiltration but not with nodal state. High L1-CAM was significantly correlated with decreased overall survival on univariate analysis and found to be an independent prognostic factor on multivariate cox regression hazard models (including pT, pN and grade, all p-values <0.05).

Conclusions: This is the first comprehensive study on L1-CAM expression in NSCLC. Particularly, epithelial expression of L1-CAM is significantly associated with shortened patient survival defining a subset of tumours with dismal prognosis.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2324.