Loss of heterozygosity in laryngeal cancer

Head and neck cancers account for about 6% of all human cancers. Molecular changes leading to the disease development and progression still remain not fully explained. Examination of loss of heterozygosity (allelic loss, LOH) using the specific microsatellite markers is a method of choice in assessing tumour suppressor genes (TSGs) localisation in human genome.

The study was performed in a group of 46 male patients, aged 42-77 years. Forty three patients underwent total laryngectomy with lymph nodectomy, two patients--chordectomy and one patient--partial laryngectomy. Tumour tissue specimens and reference peripheral blood samples were obtained during surgical resections. Standard methods were used for DNA isolation. Fluorescent multiplex PCR was used to amplify microsatellite loci included in commercially available human identification kits.

LOH was found at the following loci: BAT26, D3S1358, FGA, CSF1PO, D5S818, D8S1179, VWA, D13S317, D18S51. The highest LOH frequency was found in the tumor samples where the neighbouring cervical lymph nodes were affected but the incidence of LOH at BAT26 was statistically insignificant (p = 0.07).

High incidence of LOH is considered an unfavourable prognostic factor accompanying an aggressive nature of the tumour and indicating an involvement of certain genome regions in cancerogenesis. In head and neck cancers LOH was found on the following chromosomes: 3p, 5q, 8p, 9p, 9q, 11q, 17p, 17q, 18p, 18q.