Background: The use of either mitotane or chemotherapy in the treatment of advanced adrenocortical carcinoma (ACC) has led to scanty and controversial results. The recent finding that mitotane is able to reverse in vitro multidrug resistance has provided a rational basis for combining this agent with cytotoxic drugs. The association of mitotane with etoposide, doxorubicin, and cisplatin (EDP) in the treatment of patients with advanced, inoperable ACC was tested in an Italian multicenter Phase II trial.
Methods: Twenty-eight patients (18 women and 10 men; median age, 47 years; range, 27-65 years) with measurable disease were enrolled in the study and evaluated for toxicity and response. There were 18 patients with clinical and/or biochemical evidence of steroid hypersecretion. An EDP schedule (etoposide 100 mg/m2 on Days 5-7, doxorubicin 20 mg/m2 on Days 1 and 8, and cisplatin 40 mg/m2 on Days 1 and 9) was administered intravenously every 4 weeks; concomitantly, patients were given up to 4 g/day of oral mitotane or the maximum tolerated dose, without any interruption between chemotherapy cycles.
Results: According to World Health Organization criteria, complete response was achieved in 2 patients and partial response in 13, for an overall response rate of 53.5% (95% CI, 35-72%). Stable disease was observed in 8 patients and progressive disease in 5. Responses occurred in patients with both functioning and nonfunctioning tumors, and more often in those bearing lymph node and lung metastases. Time to progression in responding patients was 24.4 months. Generally, the EDP regimen was well tolerated. Only 4 patients received reduced doses, whereas 3 discontinued early chemotherapy due to toxicity. The addition of mitotane increased neurologic and gastrointestinal side effects. Due to these additional toxicities, only 9 patients regularly took the drug at the planned dose (4 g/day); 11 received the maximum tolerated dose of 3 g/day, 6 received 2 g/day, and 1 received 1 g/day. Mitotane was also responsible for raised serum levels of cholesterol and triglycerides. A complete hormone response (normalization of altered biochemical parameters) was observed in 9 of 16 evaluable patients with functioning tumors.
Conclusions: EDP plus mitotane combination chemotherapy appears to be active and manageable treatment for patients with advanced ACC.