Distinct chromosomal deleted regions defining different subsets of head and neck tumors

The aim of this work is detecting the loss of heterozygosity (LOH) and its relationship with the development and progression of head and neck cancer. Matched normal and tumor DNA from 81 patients with head and neck cancer wer e examined fur LOH using six microsatellite repeat markers mapped to chromo somal regions 3p13, 6q13, 9p21. 11p15, 17p13.1, and 17q22. LOH frequency at a locus ranged From 21% to 55%. The highest frequencies were at 3p (41%). 9p (48%), and 17p (54%). Thirty-two of 81 tumor samples showed allelic loss at more than one region. significant associations were round between LOH a t 3p and 9p (P = 0.001), 9p and 11p (P = 0.03), and 9p anti 17p (P = 0.007) . LOH at 11p was frequent in tumors From the oral cavity (5/17), oropharynx (2/7), and hypopharynx (5/10), but absent in tumors from the larynx (0/11) (P = 0.02), and LOH at 17q was observed in tumors from oral cavity (10/30) and hypopharynx (3/9), but not in tumors from the oropharynx (0/10) or lar ynx (0/13) (P = 0.003). In addition to that, the occurrence of allelic loss es at 9p and 17p strongly correlates to tobacco smoking (P = 0.03 and P = 0 .006, respectively) and alcohol intake (P = 0.01 and P = 0.005, respectivel y). These results suggest that tumors fi-om different sires have different LOH patterns and corroborate with epidemiological data implicating tobacco and alcohol in the etiology of head and neck tumors.