SAT-154 Clinical Presentations and Outcomes of Adrenal Metastases Vary Based on Etiology

Background: Adrenal metastases occur in 1–8% of patients with an adrenal mass. Recognizing patterns in the presentation of adrenal metastases is critical in dictating management. Objective: To describe the presentation of patients with adrenal metastases and identify baseline characteristics predicting the etiology. Methods: A retrospective analysis of adult patients diagnosed with adrenal metastases between 2000–2019 at a single institution tertiary center was performed. Partial cohort analysis is presented. Results: In 327 patients (127 (39%) women, median age at diagnosis of 67 years (range 25–92)), median tumor size was 2.7 cm (range 0.5–15), and 99 (30%) had bilateral tumors. While most patients (188, 57%) were found to have an adrenal mass during cancer staging, 117 (36%) were found incidentally and 22 (7%) based on symptoms. Adrenal metastases originated from the lung (118, 36%), genitourinary (GU) (100, 31%), gastrointestinal (GI) (47, 14%), and other (43, 13%) organ systems. Unknown primary malignancies were diagnosed in 19 (5.8%) patients. Male predominance was observed in GU (72%) and lung (62%) metastases, but equal gender distributions were noted for all other metastases, p=0.01. Patients with GI and lung metastases were diagnosed with smaller tumors (median 2.1 and 2.6 cm, respectively) compared to those with GU (median 3.5 cm) and other (median 4 cm) metastases, p=0.0008. Bilateral metastases were more frequently found in patients with lung (37%) and other (38%) metastases compared to those with GI (17%) and GU (24%) metastases, p=0.01. Of 99 (30%) patients with bilateral metastases, 23% developed primary adrenal insufficiency (PAI), most commonly in those with lung (36%) and GU (30%) malignancies. Only 123 (38%) patients were evaluated by an endocrinologist. Pheochromocytoma work-up was more often pursued if seen by an endocrinologist (71% vs. 15%, p<0.0001) in 118 (36%) patients. Adrenalectomy was performed in 94 (29%) patients, most frequently in those with GU metastases (57%), compared to only 10% of those with lung metastases. Patients were followed for a median time of 14 months (range 0.1–181), and 222 (68%) died. GU metastases carried the best prognosis with a mortality rate (MR) of 43%, as opposed to a MR of >70% in all other metastases, with lung metastases carrying the worst prognosis (MR of 85%). Multivariate analysis revealed that mortality was associated with increasing age (OR 1.3 (95% CI 1.04–1.6) for each decade) and metastasis subgroup (lung vs. GU: OR 7.2 (95% CI 3.7–14)). Conclusion: Adrenal metastases most commonly originated from lung, GU and GI malignancies, with a third of patients discovered incidentally. Bilateral metastases occurred in 30% of patients, where 1 in 4 developed PAI. Only a minority were evaluated by an endocrinologist or had work up for pheochromocytoma. Mortality was highest in those with adrenal metastases originating from the lung.