Chromosome 8 copy numbers and the c-myc gene amplification in non-small cell lung cancer

Amplification of the c-myc gene has been reported in non-small cell lung cancer(NSCLC). We performed dual color fluorescence in situ hybridization(FISH)to detect amplifications of the c-myc gene on chromosome 8 to evaluate the relationship between these possible abnormalities and pathological stage. Tumor tissue samples were obtained from 29 patients of NSCLC in Stage I(n=15)and III(n=14)who underwent lobectomy at Saitama Cancer Center. Samples were analyzed for chromosome 8 centromere and c-myc gene by dual color FISH. The numerical aberration rate of chromosome 8 was 36.8±20.3% in Stage I and 40.6±24.8% in Stage III. The amplification rate of c-myc gene was 48.3±15.2% in Stage I and 57.4±17.0% in Stage III. There was a significant difference in the numerical aberration rate of chromosome 8 between patients who survived for 5 years or more(28.8±17.5%)and those who survived less than 5 years(44.7±23.1%). The amplification rate of c-myc gene was not different between patients who survived more and less than 5 years survival, and who survived more and less than 3 years. The 5 year-survival rate in patients who showed 40% or more of chromosome 8 aberrations(n=13)was 15.4%,which revealed significantly less than that of patients who showed less than 40% of aberrations(n=16) (56.3%). There was no difference between the 5 year-survival rate in patients whose amplification rates of c-myc gene were equal or more than 50%(n=16)and less than 50%(n=13)(25.0 % and 53.9%).The rate of chromosome 8 aberrations and the c-myc gene amplification rate were not correlated with pathological stage. However, the rate of chromosome 8 aberration showed correlation in terms of longevity of survival rate, therefore we considered the rate of chromosome 8 aberration to be an additional prognostic factor of patient with NSCLC. (J Nippon Med Sch 1999 ; 66 : 107―112)