Genetic analysis of head and neck squamous cell carcinoma and surrounding mucosa

Objective: Comparative genomic hybridization was performed on head and neck squamous cell carcinoma and surrounding mucosa to determine whether common chromosomal aberrations could be detected that would predispose an individ ual to developing a second primary tumor. Design: Biopsy specimens were taken from 19 patients with squamous cell car cinoma of the head and neck, 3 samples from each person: 1 specimen from th e tumor site and 1 each from 1 and 5 cm from the macroscopic tumor margin. Samples were snap frozen in liquid nitrogen. A portion of each distant samp le and tissue taken from immediately adjacent to the site of the tumor spec imen were sectioned and stained with hematoxylineosin, either to search by light microscopy for tumor cells or signs of dysplasia in the distant sampl es, or to determine whether the tumor specimen had substantial nontumor cel l content. Tissue adjacent to the tumor biopsy site was used because the bi opsy specimens were relatively small. Comparative genomic hybridization was performed on all samples. Subjects: Nineteen patients with newly diagnosed carcinomas of the head and neck. Results: The tumor biopsy specimens showed no substantial nontumor cell con tent, and the distant specimens were all histologically normal. The tumors showed multiple mutations: mean (SD) number of deletions, 5.4 (4.3); amplif ications, 5.2 (4.6). Deletion of chromosome 3p was seen in 13 of 19 cases a nd was associated with amplification of 3q in 10 cases. No mutations were s een in the distant biopsy specimens. Conclusions: Frequently occurring chromosomal aberrations were seen in the tumor cells, suggesting a key role for these mutations in tumor development . Screening histologically normal upper aerodigestive tract mucosa with com parative genomic hybridization does not provide information on early geneti c events that predispose a patient to developing a second primary tumor.