Correlation of transforming growth factor alpha and epidermal growth factor receptor in oropharyngeal carcinomas

Previous studies have shown increasing evidence that TGF-alpha, a ligand for the often overexpressed EGF-receptor may be important for the oncogenesis and autocrine stimulation of the proliferation in head and neck cancers. The occurrence of TGF-alpha and its relation to the EGF-receptor still remain unclear. Twenty six specimens (primaries and metastasis) of oropharyngeal squamous cell carcinomas were investigated for the presence of transforming growth Factor alpha (TGF-alpha), epidermal growth factor (EGF) and the EGF-receptor using a tissue extraction method and a ''sandwich'' immune absorbent assay. In 77% of the specimens we found TGF-alpha, all had a significant amount of EGF-receptors, no EGF was found. No significant difference was noted for metastasis and primaries. No correlation was seen to the TNM stage and to the histological grading. There was an inverse statistical correlation between the TGF-alpha and the EGF-receptor concentration. High TGF-alpha concentrations were associated with low EGF-receptor concentration. Interestingly, even high TGF-alpha concentrations showed a lower limit of EGF-receptor concentrations which could not he passed. The present investigation gives a quantitative determination of the EGF-receptors and TGF-alpha in oropharyngeal carcinomas. The results indicate that a EGF-receptor /TGF-alpha complex could be functionally important for autocrine/paracrine stimulation.