AbstractOverexpression of LAPTM4B-35 (lysosomal-associated transmembrane protein 4β-35) is associated with a poor prognosis in numerous malignant tumours. Expression patterns and effects of LAPTM4B-35 on head and neck squamous cell carcinomas (HNSCC) are unknown. The aim of this study was to investigate the prognostic relevance of LAPTM4B-35 in HNSCC. Tissue microarrays were constructed with primary tumours and associated lymph node metastases isolated from 127 patients. The expression of LAPTM4B-35 was investigated by immunohistochemistry and the results were correlated with survival data. LAPTM4B-35 in the primary tumour was highly expressed in 47.2% of the patients (60/127). LAPTM4B-35 expression was significantly associated with tumour stage. Moreover, overexpression of LAPTM4B-35 correlated with a significantly worse disease-free survival (10.23 years vs. not reached) and a higher recurrence rate (40.7% vs. 25%). High expression of LAPTM4B-35 in lymph node metastasis was found in 29.2% of cases. In 19.4% of cases, high LAPTM4B-35 expression was observed in both the primary tumour and corresponding lymph node metastases. In conclusion, our data indicates that overexpression of LAPTM4B-35 is associated with poor prognosis and may therefore serve as a new prognostic marker in HNSCC.