Different chromosomal imbalances in metastasized and nonmetastasized tongue carcinomas identified by comparative genomic hybridization.

Tumors of different metastatic behavior possibly differ in genomic constitution. We identified molecular cytogenetic differences between a group of metastasized and nonmetastasized primary tongue tumors by comparative genomic hybridization. Most frequent chromosome copy number changes for metastasized and nonmetastasized tumors were +8q (100% and 71%, respectively) and +3q (56% and 43%, respectively). Metastasized tumors showed significantly more chromosome copy number changes than nonmetastasized tumors. High copy number gains were exclusively found in metastasized tumors for 3q23-qter, 5p, 12p and 13q21-q22. Genomic imbalances occurring in metastasized tumors but not in nonmetastasized tumours were +7q21 (44%), +14q (33%), and -15q (33%). The genetic constitution of primary tongue tumors that metastasize differs from tongue tumors that do not metastasize. Our data, although obtained from a relative small group of tumors, spotlights copy number gain of chromosome region 7q21 as a potential marker for metastatic behavior.