Cisplatin combination chemotherapy induces a fall in plasma antioxidants of cancer patients

Background: Antioxidants protect the body against cellular oxidative damage and thus some of the adverse effects induced by cisplatin and other cytostatic drugs. Patients and methods: The effect of cisplatin-combination chemotherapy on concentrations of plasma antioxidants was studied in 36 cancer patients, including osteosarcoma and testicular carcinoma patients. Results: Eight to 15 days after the start of each cytostatic drug infusion concentrations of various plasma antioxidants were measured and compared to pretreatment values: vitamin C and E, uric acid and ceruloplasmin levels fell significantly (P < 0.01–0.005) and returned to baseline levels before the start of the next chemotherapy cycle. Levels of the antioxidants bilirubin, albumin and the ratio vitamin E/cholesterol + triglycerides measured three weeks after the start of chemotherapy significantly decreased compared to pretreatment levels and remained low thereafter (P < 0.001–0.002). Dietary intake of antioxidants and anthropometric measurements, evaluated in 14 patients did not change during the whole treatment period. Conclusions: Cisplatin-combination chemotherapy induces a fall in plasma antioxidant levels, that may reflect a failure of the antioxidant defense mechanism against oxidative damage induced by commonly used anticancer drugs. This probably results from consumption of antioxidants caused by chemotherapy induced-oxidative stress as well as renal loss of water-soluble, small molecular weight antioxidants such as uric acid.