[Individual sensitivity to the mutagenic agents in patients with larynx cancer]

Patients with different cancers, induced mostly by numerous mutagenic factors, present increased genetic susceptibility to mutagenic agents known as "hidden chromosomal instability". This type of genetic instability can be detected in vitro after treating chromosomes with clastogenic substances, for example by using "bleomycine test". The purpouse of our study was to evaluate a hidden chromosome instability in patients with squamous cell carcinoma of larynx (SCCL) and to establish correlations between genetic results and both histological grade of the tumor and clinical progression of disease. Cytogenetic analysis of 126 of patients diagnosed with SCCL and 98 of controls was performed in vitro on peripheral blood lymphocytes. The analysis of sensitivity to bleomycine of larynx cancer patients in relation to histological grade of the tumor proved, that increased numbers of chromosome breaks as well as and percentage of aberrant metaphases are correlated with the tumor grading. Mean number of chromosome breaks per cell (b/c) in patients with larynx cancer was 1,01 (+/- 0.43), while in the control group was 0.74 (+/- 0.29) per cell (chi2 p < 0.001). Percentage of aberrant metaphases (% am) in patients with SCCL was 42.18 (+/- 11.61) and 36.05 (+/- 10.22) in the control (chi2 p < 0.001). The group of hypersensitive patients (b/c > 1) consisted of 51.5% percent of larynx cancer patients, while in the control, hypersensitivity occurred only in 20.4% of subjects (chi2 p < 0.001). Possible chromosome instability (0.8 < b/c < 1) was found 11.9% patients with SCCL and in 20.4% of controls (not statistically significant). Increased sensitivity to bleomycine in patients with SCCL in comparison to the control group was found. Most sensitive to bleomycine was the group of patients diagnosed with SCCL graded G2 (Scheffe's test p < 0.05)