Young adults with head and neck cancer express increased susceptibility to mutagen-induced chromosome damage.

Factors that contribute to an increased prevalence of squamous cell carcinoma of the upper aerodigestive tract among young adults in the United States remain unknown. A potential etiologic factor may relate to a genetically controlled sensitivity to environmental carcinogens. This study, therefore, examined 20 young adult patients who had squamous cell carcinoma for mutagen-induced chromosome sensitivity. Lymphocytes from respective patients were cultured, exposed to the clastogen bleomycin, arrested during metaphase, and examined quantitatively for chromosome breakage. As compared with an age- and sex-matched control population, as well as a population of patients who had non-squamous cell carcinoma head and neck tumors, the young adult population with squamous cell carcinoma expressed a significantly increased number of bleomycin-induced chromosome breaks per cell. Furthermore, among the study patients, chromosome sensitivity was most apparent in the non-tobacco users and in patients less than 30 years of age. The expression of such chromosome fragility following mutagen exposure should be considered in epidemiologic studies that intend to define risk factors for development of head and neck cancer.