Carboplatin dose based on actual renal function: no excess of acute haematotoxicity in adjuvant treatment in seminoma stage I.

introductionThe practice of carboplatin dosing is not concordant among different centres and oncologists. Some clinical guidelines recommend capping of the carboplatin dose at, for example, creatinine-clearance (Crea-Cl) of 125 mL/min because of concerns of excessive toxicity. Clinical data to support such recommendations are lacking, especially in patients with seminoma.

methodsThis is a retrospective analysis of acute haematotoxicity of patients with stage I seminoma treated with adjuvant carboplatin area under the curve (AUC) 7 in routine practice in two Swiss centres in 2005-2015, and a comparison of incidence and grade (according to Common Terminology Criteria for Adverse Events v4.0) of haematological adverse events (hAEs) in patients with Crea-Cl <125 mL/min vs >125 mL/min without dose capping.

results74 patients with 229 documented measurements were included (median 3/patient). A total of 151 hAEs occurred. Platelet nadir occurred earlier than median white cell/neutrophil count (median day 15 vs day 22; P<0.0001). The majority of hAEs were mild, with more than 80% being of grade 1. Only two (2.7%) clinically relevant hAEs necessitating subsequent interventions occurred (one patient received platelet transfusion, one patient with febrile neutropaenia). Haematological toxicities were not statistically different in patients dosed with Crea-Cl >125 mL/min versus those with Crea-Cl <125 mL/min. No hAEs other than grade 1 occurred before day 10 and after day 24.

conclusionsToxicity after single-dose carboplatin AUC 7 is generally mild. No excess of toxicity occurs in patients with high Crea-Cl above 125 mL/min, and therefore dose capping is not routinely necessary. In addition, this study provides a rationale for efficient use of healthcare services without compromising patients' safety.