Abstract
<title>Abstract</title> <p>Beckground: Head and Neck squamous cell carcinomas (HNSCC) are often diagnosed in late stages with regional lymph node metastasis. L1CAM (L1 cell adhesion molecule) is known as a significant prognostic marker in solid tumours such as endometrial and colon carcinoma and is often associated with invasion into the lymphovascular space and therefore poor prognosis. Here, we investigated L1CAM´s expression in HNSCC and determined its prognostic value. Methods: We analyzed L1CAM expression by immunohistochemistry in a retrospective cohort of 233 HNSCC patients of all head and neck locations. An immunoreactive score was developed and its association with clinic-pathological characteristics and its prognostic value evaluated for overall and relapse-free survival. Results: L1CAM-staining was observed at the cell membrane and was most intense at the invasion front. Tumor size, UICC stage and the risk factor alcohol consumption could be linked to high L1CAM expression. L1CAM-status was highly associated with unfavorable outcome, for relapse free (RFS) as well as overall survival (OS). In subgroup analyses, L1CAM status was equally important for all subgroups. Only for lymph node metastasis positive (N1) and higher UICC stage (3 + 4) subgroups, L1CAM status was not significant for outcome. Conclusions: The determination of L1CAM by immunohistochemistry could be a promising additional prognostic biomarker for the outcome of HNSCC for the major anatomical sites oral cavity, oropharynx, hypopharynx and larynx.</p>