ASCO GU 2018: Management of Adrenocortical Carcinoma and Pheochromocytoma Endocrinologic Issues
He began by highlighting the common work up for the incidental small adrenal lesion >1cm. These include a low-dose dexamethasone test in order to determine if there is cortisol secretion, as well as plasma or urine metanephrine testing to evaluate for pheochromocytoma. If hypertension or hypokalemia are present, additional aldosterone and renin levels should be attained. If the lesion is large or is suspicious for an adrenocortical carcinoma, then sex hormones and steroid precursors should also be obtained. Finally imaging including CT wash-out, MRI, or FDG-PET is important if the lesion does not clearly appear to be benign on initial presentation. An important aspect of the workup is identifying patients who require pre- or post-operative medical treatment for those who require surgical intervention. Dr. Else aims for a one-step workup, and tries to minimize the number of follow-up visits in patients who are being worked up for an incidental adrenal lesion.
Every patient with pheochromocytoma who has elevated levels of pre-operative normetanephrines and those patients with hypertension pre-operatively require alpha blockade. Historically, the most common treatment agent is phenoxybenzamine, however in the recent years, this drug is often not covered by insurance due to cost, and if this occurs, doxazosin is used. If, after adequately alpha blocked, a patient has persistent tachycardia, a beta blocker can be used in conjunction. Proper pre-operative volume status is also important, as patients who become hypotensive intraoperatively who have been previously blocked do not respond to pressors.
Post-operatively, pheochromocytomas are monitored for recurrence with plasma metanephrines and chromogranin A levels. Routine imaging is not required post-operatively unless patients develop post-operative elevations in these markers, or if their tumors did not secrete these biomarkers pre-operatively.
Only about 1 in 3 patients with ACC present with symptoms of hormone excess. These aggressive tumors are typically large, with only 1% of lesions being less than 1cm in diameter, and the vast majority of them being greater than 4cm in diameter. During endocrine workup for patients with suspected ACC, 50% of patients will have a tumor that secretes hormones. It is important to identify those patients who have a glucocorticoid excess, sex steroid excess, or mineralocorticoid excess. It is particularly important to determine those who may require post-op glucocorticoid replacement. Patients with active Cushing's disease also need bisphosphonates, insulin, and infection prophylaxis peri-operatively. Treatment of cortisol excess can be treated with multiple medical therapies, including ketoconazole, mitotane, mifepristone, metapyrone, or etomidate (requires ICU setting).
Dr. Else then stressed the importance of offering patients with either pheochromocytoma or ACC genetic testing, as these two conditions are often related to a variety of genetic syndromes. Genetic testing allows the patient to be more appropriately screened for other medical problems that can arise as a result of these genetic syndromes, and also allows family members to determine if they are at risk of development of disease.
He concluded that it is important to identify patients that need specific therapies depending on their hormone production. This helps to avoid perioperative complications or adrenal insufficiency. He stressed that if there are any questions regarding the endocrinologic workup or treatment of patients with adrenal lesions, he would recommend a multidisciplinary approach and would strongly recommend the consultation of an endocrinologist with experience in treating these disease.
He concluded that it is important to identify patients that need specific therapies depending on their hormone production. This helps to avoid perioperative complications or adrenal insufficiency. He stressed that if there are any questions regarding the endocrinologic workup or treatment of patients with adrenal lesions, he would recommend a multidisciplinary approach and would strongly recommend the consultation of an endocrinologist with experience in treating these disease.
Presented by: Tobias Else, MD, University of Michigan
Written by: Brian Kadow, MD, Fox Chase Cancer Center, Philadelphia, PA at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA