Efficacy and safety of mitotane in the treatment of adrenocortical carcinoma: A retrospective study in 34 Belgian patients.

Objectives: Evaluation of patient characteristics and mitotane use in the treatment of adrenocortical carcinoma (ACC) over a 4-year period in Belgium.

Material And Methods: This was a multicentre retrospective review of the outcome of 34 patients treated with mitotane for ACC during the period [01/2008-12/2011] (12 diagnosed before and 22 diagnosed during the study period) and evaluated up to 06/2013.

Results: Patient and tumour characteristics were consistent with those generally described for ACC. Mean age at diagnosis was 46.5 years, most patients were female (62%), had functioning ACC (65%) and advanced tumours (ENSAT stages III or IV: 82%). Therapeutic mitotane plasma levels (14-20 mg/L) were achieved at least once in 70% of the cohort, after a median of 4 months, and were maintained for more than 2 months in 61% of evaluable patients. Mitotane-related adverse effects were observed in 66% of patients, were never serious, and included gastrointestinal, neurological, neuropsychological, hormonal, dermatologic and metabolic effects. Most patients (88%) discontinued mitotane, mainly due to tumour progression. Multivariate analysis showed that ENSAT stage was a prognostic factor for overall (OS) and disease-free survival (DFS); OS was also influenced independently by achievement of therapeutic mitotane plasma levels for at least two consecutive months.

Conclusion: Patient and tumour characteristics were consistent with previously published data. OS and DFS were mostly influenced by ENSAT stage at diagnosis. Achieving therapeutic levels of mitotane for at least two consecutive months seemed to positively influence OS, but such levels were not reached or sustained in some patients.