Chemotherapy-induced chromosomal damage in peripheral blood lymphocytes of cancer patients supplemented with antioxidants or placebo.
A total of 27 patients with various types of cancer were treated with cisplatin-based combination chemotherapy. Out of these, 13 patients were randomized to receive supplementation treatment with a beverage containing the antioxidants vitamins C and E, plus selenium, during chemotherapy. The antioxidant mixture was administered to investigate whether it could reduce the potential genotoxic and nephrotoxic effect of the applied chemotherapy. A placebo group of 14 cancer patients received a beverage without selenium or antioxidants. Micronuclei (MN) in cytochalasin B-blocked binucleate (BN) peripheral blood lymphocytes (PBLs) and hypoxanthine phosphoribosyl transferase (HPRT) mutants in PBLs were studied before, during and after chemotherapy as a measure for chemotherapy-induced genotoxic effects. Before chemotherapy, patients mean frequencies of MN and HPRT mutants did not differ from those in a group of 10 healthy subjects. The mean frequency of MN in patients increased significantly after one cycle of chemotherapy (P=0.002). This frequency was still elevated at 2 months after the completion of chemotherapy (not significantly). There was no significant difference in micronuclei frequency (MNF) between the antioxidant and placebo group of patients. Chemotherapy-induced frequencies of MN after three cycles of chemotherapy correlated significantly with the cumulative dose of cisplatin (r=0.58, P=0.012) and the cisplatin-mediated loss of renal function (r=0.53, P=0.03). No consistent change in HPRT mutant frequency following chemotherapy was observed in the placebo and antioxidant group of patients. In conclusion, cisplatin-combination chemotherapy resulted in a cisplatin dose-related increase of the frequency of chromosomal damage. Supplementation with antioxidants did not prevent or reduce this effect.