Micronucleus formation kinetics in buccal mucosa cells of head and neck cancer patients undergoing radiotherapy

In head and neck cancer, radiotherapy is one of the main treatment modalities besides surgery and chemotherapy either in a primary or an adjuvant setting. Radiation kills tumor cells by damaging the DNA within these cells. One of the methods to assess the degree of genomic damage is the micronucleus (MN) test. The effect of radiation therapy on the MN frequency in buccal mucosa cells has only been investigated in small studies looking at single time points or including a limited number of patients. In the present study, normal tissue buccal mucosa cells from 17 patients were analyzed for genomic damage at four different time points during radiation therapy. A clear increase was observed for every time point. Additionally, buccal mucosa cells of a cohort of 16 patients were analyzed after the end of the therapy and compared to samples from 25 patients sampled before the therapy. 10 healthy controls were included, of which 5 were sampled once, and 5 were sampled four times similar to the patients. Also, the influence of additional chemotherapy was investigated. No difference was observed between radiation-only patients and patients receiving additional chemotherapy. Age, gender, and tumor stage did not have an influence on the MN formation kinetics. (C) 2012 Elsevier Ireland Ltd. All rights reserved.