BLEOMYCIN-INDUCED CHROMOSOME SENSITIVITY - REPORT OF A COLON-CANCER FAMILY

This is a study report of bleomycin-induced chromosome sensitivity in a colon cancer family with 4 affected members and 13 nonaffected membe rs. All the 4 colon cancer patients were hypersensitive to bleomycin a nd expressed between 189-212 breaks per 100 metaphases. It is likely t hat the hypersensitive individuals have deficiencies in the mechanisms of DNA repair and recombination that are essential for maintaining th e integrity of the DNA. It is also likely that the familial colon canc er patients have a common genetic determinant that may be an important predisposing factor for cancer development. All the nonaffected membe rs except one were less sensitive to bleomycin and expressed a lower n umber of breaks. One non affected member with a one-year history of bo wel complaints was also hypersensitive to bleomycin. He expressed 207 breaks per 100 metaphses, which was as high as those of colon cancer p atients. This makes serial studies on mutagen sensitivity on colon can cer family members, for the probable development of a susceptibility m arker, necessary.