Restricted number of chromosomal regions implicated in aetiology of human cancer and leukaemia.

It has been known since the days of Boveri that neoplasia is associated with chromosomal aberration. The introduction, some 10 years ago, of chromosome banding techniques provided the impetus for the description of an immense number of such aberrations, and for the localization to individual chromosome bands of the breaks underlying the aberrations. Hypothetically, the breaks should comprise two essentially different kinds: primary breaks that are actively involved in the malignant development, and secondary breaks, coincidental to this process. In the search for a possible method to identify primary breaks in human cancer, I selected from the catalogue of chromosome aberrations now available those cases that had one single structural aberration as their sole deviation from normality. I report here that the breakpoints thus specified affect a surprisingly limited number of chromosomal regions, and conclude that these regions contain genes of prime importance to cancer development.