Prognostic significance of biological parameters in head and neck tumors -Review of the literature.

Background: Scientific research work of the last decade has been performed in order to investigate biological parameters of prognostic significance fo r head and neck squamous cell carcinoma. In contrast to other cancer types, like colon carcinoma, where tumour progression is accompanied by an almost defined sequel of gene activations and inactivations, cells of squamous ce ll carcinoma behave more heterogenously. Methods: Publications concerning t he most important immunohistochemical, molecular biological and cytogenetic prognostic markers in head and neck cancer have been analyzed. Results: Th e prognostic markers discussed in this publication have been classified int o the following areas: Apoptosis, cell cycle regulation, viral infections, cytokines and growth factors/growth factor receptors, angiogenesis and hypo xia, proteinases, cell-cell contacts and cell-matrix contacts, cytokeratin fragments, chromosomal rearrangements and genetically inherited susceptibil ity to toxic reagents. Conclusions: Significant prognostic markers are impo rtant for the clinical follow-up of patients and the choice of therapeutica l approach. However, none of the factors analyzed can be used as an individ ual and universal prognostic marker at present.