Non-random distribution of chromatid breaks in lymphocytes of laryngeal squamous cell carcinoma patients

Abstract

The frequency and localization of mutagen-induced chromatid breaks in peripheral blood lymphocytes (PBLs) were investigated for association with squamous cell carcinoma (SCC) of the larynx. The case-control study was performed in 52 patients with laryngeal SCC and in 47 cancer-free controls. The analyses were based on the bleomycin sensitivity assay. The differences between cases and controls were estimated using Mann-Whitney U test and unconditional logistic regression. The total number of chromatid breaks in PBLs of patients was significantly higher compared with healthy controls (p<0.0001); the increase was observed in almost all chromosomal arms. In a number of chromosomal regions, the relative frequency of breaks was higher in patients; this increase was statistically significant for 1p22, 5q31, 6q23 and 10q24. The majority of sites with the increased proportion of breaks in patients were identified as regions containing loci involved in DNA repair, cell cycle regulation, suppressor genes and oncogenes. Revealing non-random distribution of chromatid breaks specifically associated with laryngeal SSC may be instrumental for defining regions involved in the etiology of this disease.