This international, multicentre, retrospective study by Riedmeier and colleagues evaluated the relationship between mitotane dosage, plasma concentrations and anthropometric parameters in children with adrenocortical carcinoma. 

It included 50 paediatric patients who were treated between 2004 and 2023 across 18 centres. Mitotane plasma levels and dosing data were analysed, focusing on measurements within the therapeutic target range (≥14mg/l). The median mitotane dose required to achieve target levels was 87mg/kg/day, with no significant difference compared with doses used when plasma levels were below target. While body weight and body surface area correlated with absolute daily dose, they did not significantly influence weight- or surface-adjusted dosing. In contrast, body mass index had a significant impact: patients who were underweight or of a healthy weight required substantially higher doses (mg/kg/day) than those who were overweight or obese, in order to maintain therapeutic plasma levels. These findings probably reflect mitotane’s lipophilic properties and accumulation in adipose tissue. Overall survival remained poor, reflecting advanced disease stages in most patients. 

The study highlights the highly individualised pharmacokinetics of mitotane in paediatric patients and emphasises the need for frequent therapeutic drug monitoring and management at specialised centres to optimise efficacy while minimising toxicity.

Read the full article in Endocrine Oncology https://doi.org/10.1530/EO-24-0081