Experience of mitotane successful in the treatment of metastatic adrenocortical cancer

Background. Adrenocortical cancer (ACC) is a rare malignant endocrine tumor endowed with an aggressive biological potential and a poor prognosis. Surgical adrenalectomy remains the only radical treatment for local ACC. The overall 5-year survival rate of stages with local ACC varies from 56% to 96% and depends on the level of surgical training of a specialized center and the use of adjuvant therapy. Mitotan is the only approved chemotherapeutic agent for the adjuvant treatment of both the primary tumor and relapse and metastases.Aim. To evaluate the experience of mitotane successful use in a young patient with recurrent ACC using the experience of a large medical institution.Clinical observation. Patient R., 31 years old, is under dispensary observation for recurrent adrenocortical cancer of the left adrenal gland T1N0M0 stage 1, class 3. Progression from 2015, 2017, February 2019, April 2019, September 2020 (in the bed, MTS to the left kidney, MTS to the retroperitoneal tissue, MTS to the soft tissues of the lumbar region on the left, MTS to the lungs). Eradication of the tumor tissue was performed surgically, followed by morphological confirmation of the removed foci. For the first time, the diagnosis was established at the age of 23 during an examination for Itsenko-Cushing’s syndrome. Morphologically, the diagnosis of ACC was established after a histological examination of the tumor biopsy obtained by left-sided adrenalectomy (adrenocortical cancer, ki67 up to 20%).During a scheduled dispensary examination in September 2020, according to CT scan of the chest with contrast, two foci were identified in the right lung: in C1 — 10 * 15 mm, in C2 — 30 * 21 mm. By decision of the council (consisting of an oncologist-endocrinologist, a thoracic surgeon and a chemotherapist), a decision was made to prescribe mitotane with dose titration under the control of the level of mitotane in the blood until it reaches 14–20 ng/l, without morphological examination of the foci. Hypocorticism was corrected by the simultaneous use of hydrocortisone with mitotane at a dose of 20 mg per day under the control of ACTH levels. In X-ray evaluation by CT of the chest with a frequency of 3 months, the therapeutic effect in the form of a decrease in the size of the foci (RESIST1.1) occurred in the first 3 months. Mitotan was canceled in November 2021 after complete regression of tumor foci according to CT scan of the chest (pneumosclerosis areas 10*4 mm). Currently, the patient is receiving hormone replacement therapy with hydrocortisone 25 mg per day and is under dispensary observation.Conclusion. Clinical observation has demonstrated the successful use of mitotane in the treatment of metastatic adrenocortical cancer.