title: The quantitation of sister chromatid exchanges in lymphocytes of cancer patients at intervals after cytotoxic chemotherapy.
abstract: Venous blood was taken from patients with cancer, prior to and up to 42 days after the administration of cytotoxic chemotherapy. Lymphocytes were stimulated to divide in vitro, and examined for sister chromatid exchanges (SCEs). Cyclophosphamide rapidly increased the frequency of SCE, which returned to approximately double the control value 24 hr after administration. The remaining SCEs disappeared more slowly. There was a positive correlation between the dose of drug and the frequency of SCE measured immediately and 4 hr, 20 hr and 21 days after treatment. As patients received successive courses of treatment the number of SCEs generally increased from about 0.14 to 0.25 per chromosome. After this, further chemotherapy was often less effective in inducing them. The presence of SCEs in peripheral blood lymphocytes may be a useful indicator for the occurrence and persistence of alkylating metabolites, residual damage in the DNA and individual responses of patients to a standard regimen.
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics; D001984:Bronchial Neoplasms / Q000188:drug therapy / Q000235:genetics; D003434:Crossing Over, Genetic / Q000187:drug effects*; D003520:Cyclophosphamide / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000648:ultrastructure; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000235:genetics*; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D003520:Cyclophosphamide