Bourdeau, Isabelle

1 Background: The ESE-ENSAT guidelines on ACC management suggest adjuvant mitotane for patients at high risk of recurrence. This indication has limited evidence base, lacking results from randomized controlled trials. No suggestion for or against adjuvant mitotane in low-risk patients was given, since studies did not stratify patients for prognosis. The randomized controlled study ADIUVO compared the efficacy of adjuvant mitotane treatment vs. observation in prolonging recurrence-free survival (RFS) in patients at low-intermediate risk of recurrence. Methods: The main inclusion criteria were: stage I-III ACC, R0 surgery, and Ki-67 ≤10%. Patients were randomly assigned 1:1 to adjuvant mitotane or observation. The primary endpoint of the study was RFS. Patients who refused randomization were eligible for the ADIUVO OBSERVATIONAL study. In this prospective, observational study, patients were managed as in ADIUVO except for randomization. A total of 91 patients were enrolled in ADIUVO, 45 in the mitotane and 46 in the observation arm. Baseline characteristics of patients were perfectly matched between the 2 arms: median age, 51 vs. 50.5 years; female, 73% vs. 67%; stage I, 20% vs. 26%; stage II, 67% vs. 63%, stage III, 13% vs. 11%; ACC secretion 44% vs. 36%; Weiss 5 vs. 5; respectively. In ADIUVO OBSERVATIONAL, 42 patients were treated with mitotane and 53 were untreated. Baseline characteristics of patients were matched between the 2 groups and with mitotane and observation groups in ADIUVO. Thus, the ADIUVO OBSERVATIONAL cohort was analyzed in parallel to deal with the lower than expected recruitment in ADIUVO. Results: In the ADIUVO study, recurrences were 8 in the MIT and 11 in the OBS arm, while deaths were 2 and 5, respectively. RFS and overall survival (OS) did not significantly differ between the 2 arms. In the OBS arm, the HR for recurrence was 1.321 (95%CI, 0.55-3.32, p = 0.54) and HR for death 2.171 (95%CI, 0.52-12.12, p = 0.29). The survival analysis in the ADIUVO OBSERVATIONAL study confirmed that of ADIUVO. Given the outcome of both studies, the NNT is 55. Conclusions: ACC patients at low-intermediate risk of recurrence after surgery are a minority; however, they show a far better prognosis than expected (5-yr RFS is 75%) and do not benefit significantly from adjuvant mitotane. The results of the ADIUVO study do not support routine use of adjuvant mitotane in this subset of patients, who may thus avoid a potentially toxic treatment. This is an important step toward personalization of ACC care. Clinical trial information: NCT00777244.

Abstract Context The role of cytoreduction of adrenocortical carcinoma (ACC) remains poorly understood. Objective To analyze the impact of cytoreductive surgery of the primary tumor in patients with metastatic ACC. Design and Setting We performed a multicentric, retrospective paired cohort study comparing the overall survival (OS) in patients with metastatic ACC who were treated either with cytoreductive surgery (CR group) or without cytoreductive surgery (no-CR group) of the primary tumor. Data were retrieved from 9 referral centers in the American-Australian-Asian Adrenal Alliance collaborative research group. Patients Patients aged ≥18 years with metastatic ACC at initial presentation who were treated between January 1, 1995, and May 31, 2019. Intervention Performance (or not) of cytoreductive surgery of the primary tumor. Main outcome and measures A propensity score match was done using age and the number of organs with metastasis (≤2 or >2). The main outcome was OS, determined from the date of diagnosis until death or until last follow-up for living patients. Results Of 339 patients pooled, 239 were paired and included: 128 in the CR group and 111 in the no-CR group. The mean follow-up was 67 months. Patients in the no-CR group had greater risk of death than did patients in the CR group (hazard ratio [HR] = 3.18; 95% CI, 2.34-4.32). Independent predictors of survival included age (HR = 1.02; 95% CI, 1.00-1.03), hormone excess (HR = 2.56; 95% CI, 1.66-3.92), and local metastasis therapy (HR = 0.41; 95% CI, 0.47-0.65). Conclusion Cytoreductive surgery of the primary tumor in patients with metastatic ACC is associated with prolonged survival.

Abstract Background: The ESE-ENSAT guidelines on the management of adrenocortical carcinoma (ACC) suggest adjuvant mitotane for patients at high risk of recurrence following radical surgery. This indication has a limited evidence base, lacking results from randomized controlled trials. No suggestion for or against adjuvant mitotane in low-risk patients was given, since studies did not stratify patients for prognosis. The randomized controlled study ADIUVO compared the efficacy of adjuvant mitotane treatment vs. observation in prolonging recurrence-free survival (RFS) in ACC patients at low-intermediate risk of recurrence. Methods: The main inclusion criteria were: stage I-III ACC, R0 surgery, and Ki-67 ≤10%. Patients were randomly assigned 1:1 to adjuvant mitotane (MIT) or observation (OBS). The primary endpoint of the study was RFS. Patients who refused randomization were offered inclusion in the ADIUVO OBSERVATIONAL study. In this prospective, observational study, patients were managed as in the ADIUVO study. A total of 91 patients were enrolled in ADIUVO, 45 in the MIT and 46 in the OBS arm. Baseline characteristics of patients were perfectly matched between the 2 arms: median age, 51 vs. 50.5 years; female, 73% vs. 67%; stage I, 20% vs. 26%; stage II, 67% vs. 63%, stage III, 13% vs. 11%; ACC secretion 44% vs. 36%; Weiss 5 vs. 5; respectively. In ADIUVO OBSERVATIONAL, 42 patients were treated with mitotane and 53 were untreated. Baseline characteristics of patients were matched between the 2 groups and with MIT and OBS groups in ADIUVO. Thus, the ADIUVO OBSERVATIONAL cohorts could be analyzed in parallel to those of ADIUVO. Results: In the ADIUVO study, recurrences were 8 in the MIT and 11 in the OBS arm, while deaths were 2 and 5, respectively. RFS and overall survival (OS) did not significantly differ between the 2 arms. Tumor size was a predictor of RFS in multivariable analysis. In the OBS arm, the HR for recurrence was 1.321 (95%CI, 0.55–3.32, p=0.54) and HR for death 2.171 (95%CI, 0.52–12.12, p=0.29). The survival analysis in the ADIUVO OBSERVATIONAL study confirmed the findings of ADIUVO. Given the outcome of both studies, the NNT is 55. Conclusions: ACC patients at low-intermediate risk of recurrence after surgery are a minority; however, they show a far better prognosis than expected (5-year RFS is about 75%) and do not benefit significantly from adjuvant mitotane. The results of the ADIUVO study do not support routine use of adjuvant mitotane in this subset of patients, who may thus avoid a potentially toxic treatment. This is an important step toward personalization of ACC care.

Adrenocortical carcinoma (ACC) is an orphan disease lacking effective systemic treatment options. The low incidence of the disease and high cost of clinical trials are major obstacles in the search for improved treatment strategies. As a novel approach, registry-based clinical trials have been introduced in clinical research, so allowing for significant cost reduction, but without compromising scientific benefit. Herein, we describe how the European Network for the Study of Adrenal Tumours (ENSAT) could transform its current registry into one fit for a clinical trial infrastructure. The rationale to perform randomized registry-based trials in ACC is outlined including an analysis of relevant limitations and challenges. We summarize a survey on this concept among ENSAT members who expressed a strong interest in the concept and rated its scientific potential as high. Legal aspects, including ethical approval of registry-based randomization were identified as potential obstacles. Finally, we describe three potential randomized registry-based clinical trials in an adjuvant setting and for advanced disease with a high potential to be executed within the framework of an advanced ENSAT registry. Thus we, therefore, provide the basis for future registry-based trials for ACC patients. This could ultimately provide proof-of-principle of how to perform more effective randomized trials for an orphan disease.