Genetic analysis of head and neck squamous cell carcinoma using comparative genomic hybridisation identifies specific aberrations associated with laryngeal origin.

Head and neck squamous cell carcinoma (HNSCC) demonstrates significant differences in the biological and clinical behaviour of tumours found at different sub-sites. We investigated the genetic profiles of 68 carcinomas (larynx n=35, hypopharynx n=19, oropharynx n=14) using chromosomal comparative genomic hybridisation in order to identify sub-site specific differences. Multiple genetic aberrations were found throughout the tumour genomes, including +3q (82%), -3p (75%), +8q (66%), +5p (49%), +7q (49%), +1q (47%), -4p (46%), -11q (46%), -13q (46%), -5q (44%), +11q (43%) and +12p (43%). The mean number of chromosomal arms with at least one aberration was 15. Laryngeal carcinomas (LSCC) were found to have significantly more aberrations on chromosomal arms than oropharyngeal carcinomas (OpSCC); (mean of 17 vs. 11, respectively (p=0.011). It was noted that -4p, +8q, +12q, and -18q were significantly associated with LSCC when compared with both hypopharyngeal SCC (HpSCC) and OpSCC. HpSCC was significantly associated with -2q whereas no aberrations were found to be significantly associated with OpSCC. In conclusion a large number of common chromosomal aberrations are associated with HNSCC however in addition further aberrations are significantly associated with individual sub-sites of head and neck cancer. These aberrations may be responsible for the diverse biological behaviour of these different tumour types. Further research is required to identify the specific genes associated with these chromosomal regions and evaluate their individual impact on disease progression.