7230 Complete Nine Years Disease Free Survival In A Patient With Metastatic Adrenocortical Carcinoma Following Systemic Chemotherapy Including Streptozotocin And Mitotane

Abstract Disclosure: L.M. Martel: None. H.J. Olney: None. A. Lacroix: None. Background: Metastatic adrenocortical carcinoma (ACC) in adults carries a very poor prognosis with rare complete remissions (CR) following local and systemic therapies. Combined therapy with mitotane and etoposide, doxorubicin, cisplatin (EDP) provided better response rate than mitotane and streptozotocin (N Engl J Med. 366: 2189, 2012). We report a patient with stage 4 ACC in long-term CR following systemic therapy which included 21 cycles of second-line streptozotocin and mitotane (SM) within the FIRM-ACT trial (NCT00094497). Clinical Case: A 56 y.o. male, presented acute left flank pain at a regional hospital. CT scans showed a 9.6 cm, 31 HU heterogeneous left adrenal mass and a 1.4 cm superior right lung nodule and centimetric mediastinal adenopathy. Hormonal testing revealed normal urinary metanephrines, cortisol after 1-mg DST, ARR, DHEAS and testosterone levels. In Aug 2014, left adrenalectomy, nephrectomy, splenectomy and partial pancreatectomy were complicated by infections, pulmonary emboli and myocardial infarction. Pathology confirmed a 15 cm, 750 gr, poorly differentiated ACC (Weiss 8/9; pT3, Ki-67 not reported). Two months later, the right 1.5 cm lung nodule, 2 new subcentimetric lung nodules and single mediastinal and retroperitoneal adenopathy presented high SUV uptake on an FDG-PET scan. At referral to our center, EBUS biopsy confirmed metastatic ACC in a mediastinal lymph node. Mitotane and hydrocortisone were introduced in Nov 2014 and EDP in December 2014. Maximal mitotane dose was 6 gr daily, but was reduced to maintain mitotanemia within therapeutic range. In Feb 2015, a 4.6 cm post-surgical adrenal bed mass was present, but later imaging showed decreasing size of lesions in the adrenal bed, mediastinal and lung nodules. Following responsive disease at 3 cycles, restaging imaging at 6 cycles of EDP, showed a mixed response. Second line chemotherapy with SM was also indicated by cardiac toxicity (LVEF decreased to 34%). During and after 21 SM cycles, restaging CT and FDG-PET scans showed CR of abdominal lesions in February 2016 and of thoracic lesions in December 2021. The patient continues Mitotane (1.5 g/d twice weekly and 1 g/d x 5 days weekly) at therapeutic levels with acceptable tolerance. Annual FDG-PET and CT thorax, abdomen and pelvis, last in October 2023, show no evidence of recurrence.Complications of therapy other than cardiac include adequately replaced adrenal and thyroid insufficiencies, osteoporotic vertebral fractures and peripheral neuropathy treated with antalgic medication. Conclusion: This case illustrates that, although rare, complete long-term remission of advanced metastatic ACC can occur in patients receiving systemic combination chemotherapy including SM and should be considered in patients with advanced ACC when EDP does not achieve a stable response and can be continued until toxic limitations, in our case peripheral neuropathy. Presentation: 6/2/2024