Endocrine Abstracts

Introduction: Mitotane-o’p-DDD belongs to insecticides (DDT pesticide contamination), it is the only drug registered by the FDA in treatment in adrenocortical carcinoma (ACC). Treatment effect is controled by mitotane concentration in the blood.

Aim: The aim of the study is to evaluate the effectiveness of mitotane treatment in patients with adrenocortical cancer.

Material and methods: We retrospectively reviewed data on ACC patients (n=204) treated with o,p′DDD (n=117) between 2002 and 2017. Finally, a total number of 55 patients was included in the study. In these patients, we analysed a graph of mitotane concentrations during the course of therapy. Therapeutic window of mitotan was set according to the characteristics of the medicinal product (FDA) at 14-20 mg/l. Patients were divided into two groups. For the study group, the inclusion criterion was to maintain the concentration window of mitotane in the plasma least at 50% of the treatment time. The study group included 17 people (31% of patients) The comparative group group consisted of those who did not reach the therapeutic window, 38 patients (69%). We observed patients from both groups in time one year intervals after the inclusion of mitotane therapy. In the evaluation of the effectiveness of the therapy, we based on the comparison of subsequent CT and MR results according to RECIST criteria. Average duration of treatment was up to 40 months in the first group of patients Average duration was of treatment was up to 28 months in the second group of patients.

Results: After a year 60% exhibited the stable disease. In the study group of patients, we observed stable disease in 82% of patients who is 23% (N=4) of patients had regression of the disease (P<0,05). In comparative group – stable disease was observed in only 50% of patients.

Conclusion: In conclusion, our data confirm the value of o,p′DDD plasma monitoring with ACC patients. Furthermore, our results suggest additional benefit of a targeting the o,p′DDD in terapetic window which has to be confirmed in a prospective study. In view of the limited possibilities of other therapies, the discussion on the use of mitotane remains open.