Restriction fragment length polymorphism analysis of the L-myc gene locus in a case-control study of lung cancer.

The L-myc DNA-restriction fragment length polymorphism, revealed by EcoRI, has been studied in both a lung cancer case-control framework and a cohort of 40 non-diseased unrelated individuals. No association was found between the L-myc allelic frequencies and disease status, tumor stage or lung cancer histology. A strong association was, however, observed between the L-myc allelic frequencies and ethnic origin (black or white) of the subjects. Among American whites the allelic distribution at the L-myc proto-oncogene locus was almost identical to that previously reported for Japanese subjects. Among the American black population there was a significantly higher frequency of the presence of the polymorphic EcoRI restriction site in the second intron of the L-myc proto-oncogene. These data emphasize the importance of conducting epidemiologic studies that control for ethnic factors and indicate that L-myc EcoRI allelotypes do not appear to be predictive of lung cancer risk or disease status in American blacks and whites.