Mutagen sensitivity in patients with laryngeal and oropharyngeal carcinomas

Background: Carcinogenesis in the larynx and oropharynx is often associated with excessive exposure to tobacco smoke and alcohol. However, attention i s increasingly being focused on genetically determined mutagen sensitivitie s and on the mutagenic impact of xenobiotics. The purpose of this study was to evaluate the genotoxicity of phthalates (plasticizers widely used in sy nthetic materials), as well as nitrosamines and polycyclic aromatic carbohy drates, on laryngeal and oropharyngeal epithelia and peripheral lymphocytes of patients with laryngeal and oropharyngeal carcinomas. Methods: The come t assay was used to detect induced DNA strand breaks. Macroscopically healt hy supraglottic and oropharyngeal epithelia of patients with laryngeal and oropharyngeal tumors, respectively, and lymphocytes were investigated with dibutylphthalate (DBP), diisobutylphthalate (DiBP), N'nitrosodiethylamine ( NDELA), and benzo[a]pyrene (BaP). The Olive Tail Moment (OTM) was used to q uantify genotoxicity. Results: For the first time, the genotoxicity of DBP and DiBP was demonstrated in laryngeal and oropharyngeal epithelia, as well as in peripheral lymphocytes, of patients suffering from laryngeal and oro pharyngeal carcinomas. OTM levels for NDELA were higher than for phthalates ; levels for BaP were lower. Testing of lymphocytes and mucosa showed no si gnificant differences among the various substances. Conclusions: Phthalates show a genotoxic impact on epithelia of tumor patients. OTM levels were hi gher than in nasal and oropharyngeal mucosa of healthy donors in results re ported earlier. Thus, specific susceptibilities to these xenobiotics need t o be discussed. No such effect was demonstrated for NDELA and BaP. In tumor patients, no significant differences could be shown in mutagenic sensitivi ties in mucosal cells and lymphocytes.