GAIN OF DNA COPY NUMBER ON CHROMOSOMES 3Q26-QTER AND 5P14-PTER IS A FREQUENT FINDING IN HEAD AND NECK SQUAMOUS-CELL CARCINOMAS

Comparative genomic hybridization (CGH) was used to study genomic imba lances in 77 squamous cell carcinomas of the head and neck (HNSCC) and in four cell lines derived from oral carcinomas. Particular attention was paid to all tumors characterized by a gain of two specific chromo somal segments, i.e. 3q26-qter and 5p14-p15. The 57 tumors containing both or one of the two imbalances were compared with 20 tumors lacking both with regard to genomic complexity, as well as to associated geno mic, histopathologic and clinical peculiarities. 60% of the oral, and 66% of the non-oral cancers exhibited a grain of 3q26-qter, while agai n of 5p14-p15 was found in 66% of the oral, but only in 48% of the non -oral tumors. 48% of all tumors were characterized by both gains toget her, 26% exhibited only one of the two alterations. It could be shown that presence of both, gain of 3q26-qter and 5p14-p15, was clearly ass ociated with a significantly higher complexity of genomic changes whic h was not only expressed as a high frequency of DNA copy number altera tions (CNAs) but was also connected with a considerable number of addi tional amplifications of various chromosomal segments and a high confo rmity of the patterns of genomic imbalances in these tumors. Clear dif ferences of the extent and of the patterns of genomic imbalance could be observed between oral and non-oral tumors. With respect to histopat hological parameters, no clear association could be found for specific imbalances to the grade of differentiation, nor the invasiveness or m etastatic status of the tumors.