Nephrotoxicity of cisplatin and carboplatin in sarcoma patients: A report from the late effects surveillance system

Background. Cisplatin and carboplatin are both nephrotoxic and can induce, to a different degree, impairment in glomerular function and hypomagnesemia. Prospective longitudinal studies on these renal impairments are rare in children and adolescents. Procedure. Six hundred and fifty one sarcoma patients were investigated prospectively for nephrotoxicity in the Late Effects Surveillance System (LESS) network (median follow-up 2 years). Median cumulative dose was 360 mg/m² for cisplatin, and 1,500 mg/m² for carboplatin. Patients not treated with any platinum derivative were used as controls. Most patients (including controls) also received ifosfamide. Renal function was tested by serum magnesium, serum creatinine, and the GFR as estimated by the Schwartz formula. We evaluated incidence, dependencies, and the course ot impairments. Results. There was no observed platinum-induced reduction of glomerular function over time. After cessation of antineoplastic therapy, hypomagnesemia (<0.7 mmol/L) occurred in 12.1% (95% CI: 6.8%-19.4%) of patients after cisplatin therapy, and in 15.6% (95% CI: 5.3%-32.8%) after carboplatin therapy, in comparison with 4.5% (95% CI: 2.0%-8.7%) in patients without any treatment with platinum derivatives (P = 0.008). In all groups, the frequency of hypomagnesemia decreased with ongoing follow-up, but serum magnesium remained lower in platinum treated patients throughout the study period. Conclusion. Nephrotoxicity after treatment with cisplatin and carboplatin was mild in our study. Further studies have to show if serum magnesium is permanently decreased in platinum treated patients and it this will result in any clinically relevant impairment.