The alkaline comet assay was employed to assess the pre- and post-treatment levels of in vivo DNA damage in peripheral blood leukocytes of
cancer patients. During the study all patients were given
antineoplastic drugs, mainly as
polychemotherapy. To quantify the DNA damage, two different comet parameters were evaluated: the tail length and the tail moment. Our results indicate marked interindividual variations between baseline DNA damage in peripheral blood leukocytes recorded among
cancer patients prior to the
chemotherapy. After
intravenous administration of various
antineoplastic drugs, a significantly increased level of DNA damage in all
cancer patients compared to their pre-treatment values was recorded The highest level of DNA damage was seen following administration of
5-fluorouracil,
adriamycin, and
cisplatin (
FAP protocol). The results indicate that administration of
antineoplastic drugs in standard protocols is accompanied by significant DNA damage in peripheral blood leukocytes. In order to diminish the potential risks of developing
second neoplasms, a continuous biomonitoring of
cancer patients after the ending of
chemotherapy becomes important. Despite their limitations, present results confirm the usefulness of the alkaline comet assay as a sensitive
biomarker of exposure that enables rapid and simple detection of primary DNA damage in peripheral blood leukocytes of
cancer patients. Together with standard cytogenetic endpoints, the comet assay provides a powerful technique for the routine detection of critical DNA lesions produced after administration of
antineoplastic drugs in the clinical settings.