Adjuvant Therapy in Adrenocortical Carcinoma: Reflections and Future Directions

Adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with high risk of recurrence despite macroscopically complete surgical resection. The main predictors of ACC recurrence include advanced disease stage, incomplete surgical resection, cortisol production, certain genetic alterations, and high proliferation rate (Ki-67 proliferation index). Mitotane has been the mainstay adjuvant therapy of ACC. However, the use of mitotane is based on retrospective and occasionally conflicting evidence. As mitotane levels can take a few months before reaching therapeutic levels, there is an emerging practice of combining platinum-based chemotherapy with mitotane in the adjuvant setting. Retrospective data indicate that radiotherapy is an option for select patients, particularly those with positive resection margins. There are multiple knowledge gaps in selecting patients for adjuvant therapy. It is of great importance to establish risk calculators to predict recurrence and to implement molecular profiling of ACC to guide adjuvant therapy. The role of immunotherapy in metastatic ACC is emerging and if deemed efficacious, then future studies will be needed to ascertain the role of adjuvant immunotherapy in ACC.