Laryngeal mucosa of head and neck cancer patients shows increased DNA damage as detected by single cell microgel electrophoresis

Major risk factors for cancer of the oral cavity, pharynx and larynx are sm oking and excess alcohol consumption. Since long-term survival rates of hea d and neck cancer patients have not substantially been improved. new preven tive strategies including the use of cancer chemopreventive agents have to be developed. With the aim of developing biomarkers which can verify the ef ficacy of chemopreventive interventions, a standardised alkaline microgel e lectrophoresis (MGE) assay was applied as a sensitive and rapid tool to det ect DNA damage on a single cell level. Macroscopically normal laryngeal muc osa biopsies obtained by surgery from head and neck cancer patients (n = 29 ) and from hospital controls (n = 22) were analysed by MGE in a pilot study . As compared to controls, cells from head and neck cancer patients showed a significantly elevated DNA damage without any further genotoxic treatment (P < 0.01). We conclude that this increased background DNA damage in laryn geal epithelia could result from genetic alterations caused by smoking and alcohol leading, in accord with the held cancerisation hypothesis, to a gra dual decrease of genomic stability and malignancy. MGE should now be explor ed as a rapid screening method in larger clinical studies: (i) to identify high-risk subjects carrying cells with decreased genomic stability and (ii) to verify the efficacy of chemopreventive regimens to prevent or slow down the development of head and neck cancer in high-risk persons. (C) 2000 Els evier Science Ireland Ltd. All rights reserved.