Adjuvant Chemotherapy vs. Observation/Mitotane After Primary Surgical Resection of Localized Adrenocortical CarcInoma

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy. Despite complete resection of early-stage disease recurrence rates in ACC are very high (60%.70%). Patients with Ki67 ≥ 10% are considered at high risk for ACC recurrence, whereas patients with Ki67\<10% are considered to have low/intermediate risk for recurrence. No study are ongoing on adjuvant systemic therapy in ACC patients that are at high risk of relapse. These patients represent 70-80% of all ACC radically operated. In this setting mitotane is widely prescribed. The efficacy of mitotane is known to be dependent on the attainment of serum drug levels in the so called therapeutic range that is above 14 mg/l. However, ACC patients with high relapse risk may develop disease recurrence before mitotane serum levels attain the target concentration. Chemotherapy with cisplatin containing regimen was shown to be efficacious in the management of ACC in few phase II trials. Based on the background, there is a strong rationale of administering chemotherapy in radically operated ACC patients with high risk of relapse defined as follows: stage I-III ACC (according to the ENSAT classification) with either microscopically complete resection (R0), microscopically positive margins (R1), or undetermined margins (RX) and Ki67≥10% (for a further definition of this condition, see the study population paragraph). In clinical practice, adjuvant mitotane alone or cisplatin-based chemotherapy or the combination of both are used worldwide in patients at high risk of relapse, but there is no prospective validation of these treatments. The investigators will test the efficacy of the combination of cisplatin plus etoposide (plus/minus mitotane according to the investigator preference) in comparison with the actual best routine practice consisting of mitotane or no therapy (according to the personal belief of clinical investigator). This study is parto of the international trial registry ADIUVO-2 coordinated by MD Anderson Cen