Genetic imbalances in preinvasive tissue of hypopharynx provide evidence for cytogenetic heterogeneity

Multiple chromosomal aberrations have been reported in head and neck squamo us cell carcinoma (HNSCC). But less information is available on specific pa tterns of chromosomal amplifications which distinguish different areas of h ead and neck tumors. To elucidate genetic mechanisms causing the aggressive growth and high proliferation of hypopharyngeal squamous cell carcinoma (S CC), we performed reverse chromosome painting (RCP) on a total of eight hyp opharyngeal SCC including invasive carcinoma and preinvasive tissue. Five h ypopharyngeal invasive carcinomas showed amplifications on chromosome 3q. F urthermore, we detected gains on chromosmes 11q and 6p. Compared to the his tologically classified preinvasive tissues, we found amplified alterations on chromosome 6p, I Iq and 12q, but none of them showed gains on chromosome 3q. This observed heterogeneity in hypoparyngeal SCC might reflect a speci fic role of chromosome 3q as a late event in the highly invasive capacity o f these SCC.