Comparison of three assays for genetic effects of antineoplastic drugs on cancer patients and their nurses

Three assays have been compared for their ability to detect genetic damage caused by antineoplastic drugs in cancer patients and possible damage in the nurses who administered these drugs. The assays were sister chromatid exchanges (SCE) and chromosomal aberrations in peripheral blood lymphocytes, and the Salmonella/mammalian microsome assay on urine. Three comparisons were made: 1) patients before versus after treatment; 2) the administering nurses immediately after their work period versus after a few days off that followed (work and off-work); 3) the exposed nurses versus other nurses who did not administer antineoplastic drugs (controls). The SCE assay detected the treatments in all eight patients from whom complete data were obtained, and was positive in two nurses with a long history of smoking. The Salmonella/mammalian microsome assay detected eight of ten treatments in patients but failed to detect smokers. Four of nine patients receiving treatment were detected by the analysis of chromosomal aberrations. The SCE assay did not distinguish between the work and off-work samples in either the exposed or control nurses. The exposed nurses, as a group, had slightly fewer SCEs than the controls due to the two smokers detected in the latter group. Chromosomal aberration was the only assay which showed significant difference between the two samples of the exposed nurses and, consequently, between the exposed and control nurses. These differences, however, arose primarily from a higher frequency of aberrations found among the exposed nurses in samples taken after a few days away from work, rather than at the end of their work period. There is no evidence that the increase was connected to occupational exposure.