Abstract No. 211 Early hepatic arterial embolization or concomitant immunotherapy are associated with improved overall survival in patients with metastatic adrenocortical carcinoma

To evaluate factors associated with overall survival and local tumor progression-free survival after hepatic arterial embolization (HAE) of metastatic adrenocortical carcinoma (ACC). This is a retrospective Institutional Review Board approved single-institution study with 16 patients (9 women, 7 men; median age, 46 years; range 19-73) with ACC that underwent HAE between 2010 and 2019. Patients were divided into three groups: systemic therapy-naïve (n = 5), chemotherapy-refractory (n = 6), and immunotherapy (n = 5). Variables including treatment history, functional status of tumor, tumor histology, tumor burden, procedure details, and complications were also analyzed. Overall survival (OS) and local tumor progression-free survival (LPFS) were estimated using the Kaplan-Meier method and hazard ratios were estimated using Cox proportional hazards model. Radiographic responses (complete response [CR], partial response [PR], stable disease [SD], and progressive disease [PD]) at 3 months were evaluated by mRECIST criteria. Median OS was 27.7 months (95% Confidence Interval [CI] = 0-56 months). Systemic therapy-naïve group (hazard ratio [HR] = 0.15, CI = 0.02-0.9) and immunotherapy group ([HR] = 0.09, CI = 0.01-0.7) had prolonged OS compared with the chemotherapy-refractory group (P = 0.01). Median LPFS from time of HAE was 10 months (95% confidence interval [CI] = 2.4-17 months).Tumor burden < 25% was associated with significantly longer LPFS (P = 0.008). Objective response (OR) was observed in 9/16 patients (56%) (CR in 5/16 (31%) and PR in 4/16 (25%) patients), while 5/16 (31%) had SD and 2/16 (13%) had PD. 7/16 (44%) patients had hormone-secreting tumors (3/5 in systemic-naïve group, 2/5 in immunotherapy group, and 2/6 in chemo-refractory group). This study demonstrates an association between early HAE or concomitant immunotherapy and improved OS in patients with metastatic ACC. Low tumor burden is associated with longer LPFS.