A-296 impact of en bloc extended r0 resection on oncologic outcome of stage iii adrenocortical carcinoma

Abstract Background In locally advanced adrenocortical carcinoma (ACC) (ENSAT stage III – S-III) R0 surgery, involving en bloc extended resection, is the only potential curative treatment. We evaluated oncologic outcome and complications rate in S-III patients who underwent extended resection in comparison with stage I/II (S-I/II). Methods Among 931 adrenalectomies over 25 years (1997–2022) in a tertiary referral center, medical records of ACC patients were reviewed, excluding stage IV patients. Results Forty-one patients were identified: 6 S-I patients (14.6%), 30 S-II (73.2%) and 5 S-III (12.2%). The latter underwent extended en bloc resection (1 partial and 2 radical nephrectomies, 1 right hepatectomy and 1 renal vein thrombectomy). Minor complications (Clavien-Dindo ≤ 2) were observed in 11.5% of S-I/II patients and 20% of S-III (p=NS). Adjuvant treatments included: mitotane (all but 1 S-I patients), chemotherapy (2 S-II and 1 S-III) and radiotherapy (3 S-II). Four S-II patients (13.3%) developed locoregional recurrence (2 lodge, 1 paracaval nodes and 1 peritoneal) (median 21 months). Metastatic disease occurred in 13 (43.3%) S-II and 1 (20%) S-III patients. At a median follow-up of 108 months, all but 8 S-II patients were alive, with recurrent disease in 9 S-II (2 regional, 7 distant) and 1 S-III (lung). No difference was observed between S-I/II and S-III in terms of DFS and OS (p=NS). Conclusion OS and DFS of S-III ACC patients undergoing extended en bloc R0 resection were comparable to those of SII/III, without increasing postoperative morbidity. Multi-Institutional studies are necessary to validate these results.