Long-term platinum excretion in patients treated with cisplatin

The purpose of this study was to determine long-term renal platinum excretion after chemotherapy with cisplatin. We examined urinary platinum concentrations in 23 men at 150-3022 days after anticancer treatment for testicular neoplasm. Spot urine samples were analyzed by voltammetry. This new, subtle method with a detection limit of 2 pg platinum allows determination of even the natural background level. Urinary platinum concentrations in our patients ranged between 0.74 and 77.24 micrograms/g creatinine, depending on the total delivered dose and follow-up period. Regression analysis of the data showed two phases of long-term renal platinum excretion, one occurring at between 150 and 900 days of follow-up and the other with an onset at 900 days after cisplatin administration (r1(2) = 0.82, r2(2) = 0.88). Two biological half-lives of 160 and 720 days were calculated. Our results show that urinary platinum concentrations determined at 8 years after cisplatin therapy are 40 times higher than the background level (up to 0.02 micrograms/g creatinine). Our findings on the long-term pharmacokinetics of this anticancer agent may facilitate further studies on sites of platinum storage in the human body as well as clinical studies on the late adverse effects of cisplatin.