Malignant primary adrenal
tumors are rare forms of
cancer with an estimated incidence of two to ten new cases per one million inhabitants per year. The 5-year survival rate for
adrenocortical carcinoma is approximately 35%, whereas the 10-year survival rate of malignant
pheochromocytoma reaches 40%. Clinical studies support repeated surgery as the mainstay of treatment, either with curative or palliative intention. For
adrenocortical carcinoma, adjunctive treatment with oral
mitotane leads to well-documented improvement of survival. Rare malignant
pheochromocytomas with distant
metastases are preferably treated by 131I-MIBG.
Chemotherapy is reserved for unresectable
tumors without sufficient response to
mitotane or 131I-MIBG, respectively.
Cisplatin and
etoposide as single
therapy, or in combination with
doxorubicin or
etoposide, appear to be effective in
adrenocortical carcinoma. Malignant
pheochromocytoma may be treated with
vincristine,
dacarbazine, and
cyclophosphamide. Treatment with
octreotide is currently being evaluated.
Radiotherapy is indicated if unresectable
tumor masses cause local symptoms. If symptoms of endocrine activity are not sufficiently controlled by measures aiming at
tumor mass reduction, specific inhibitors of
hormone synthesis or action are available.
Ketoconazole is widely used for
adrenocortical carcinoma, and
phenoxybenzamine and
metyrosine are available for malignant
pheochromocytoma. This review provides guidelines for rational disease management based on still scanty clinical evidence.