[Chromosome instability and cancer].

Chromosome instability is considered to be a probable candidate for a genetic predisposition to cancer. In order to confirm association of heritable fragile sites with cancer, an epidemiologic survey study was conducted which compared their incidence between patients of leukemia and allied diseases, and healthy subjects. The total incidence was 3.2% and 6.0% in patients and controls, which seemed to indicate that the carrier state of a fragile site is not a risk factor for cancer development. However the cases detected in the study were individually quite interesting: One was a coincident case of fra (16) (q22) and inversion of chromosome 16, and another was a coincidence of homozygous fra (17) (p12) and familial clustering of cancers. Chromosome instability, including the fragile sites, should be paid further attentions with respect to its role in the etiology of cancer.