PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent biologic therapy At least 4 weeks since prior biologic therapy (one regimen only) Chemotherapy: No concurrent chemotherapy At least 4 weeks since prior mitotane No other prior chemotherapy allowed Endocrine therapy: At least 6 weeks since prior hormonal therapy No concurrent hormonal therapy Radiotherapy: At least 4 weeks since prior radiation therapy (to less than 25% of bone marrow) No concurrent radiation therapy Surgery: Prior surgery allowed in relapsed patients with no other prior treatment