Japanese single-institution analysis of mitotane for patients with adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis. While mitotane is the only agent approved for ACC, clinical data are scarce, especially in the Asian population. We reviewed 10 patients with ACC who received mitotane as a single agent or in combination with other agents in our institution. Patient characteristics, clinical outcomes, and toxicities were analyzed. Mitotane was administered to 2 patients as an adjuvant therapy and to 8 patients for systemic control. In the latter 8 patients, 1 patient had locally advanced disease and 1 had metastatic disease at the time of initial diagnosis, whereas the other 6 patients experienced metastatic relapse at mitotane initiation. The administered regimen was mitotane alone in 7 patients, and mitotane plus cytotoxic chemotherapy in 3 patients. The initial daily mitotane dose was 3.0 g in 2 patients, 1.5 g in 7 patients, and 1.0 g in 1 patient. The median duration of treatment was 3.7 (range, 0.7-22.1) months. In 8 systemic cases, the median overall survival from chemotherapy initiation was 7.2 months, and only 1 patient survived over 1 year. The median interval from mitotane termination to death in systemic cases was 2.8 months, and the cause was progressive disease in 4 patients and toxicity (hallucination, mycobacteriosis, or liver injury) in 3 patients. As a second-line regimen, 2 systemic cases and 1 adjuvant case were enrolled in clinical trials. Our analysis exhibited extremely poor prognosis under mitotane-based regimens, and further treatment strategies are warranted to improve outcomes.