Efficacy and Safety of Radiotherapy and Systemic Treatments in Adrenocortical Carcinoma: Systematic Review and Meta-Analysis

Abstract Context Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy with a high recurrence and mortality rate even after complete resection. Therefore, intensification of adjuvant therapies is crucial, though their effectiveness remains controversial. Objective This study aimed to determine the efficacy and safety of available treatments by considering the prognostic factors affecting disease outcomes. Data Sources The search was conducted across three databases (PubMed, Embase, and Central) in October 2024. Study Selection Eligible studies compared overall survival (OS) and recurrence-free survival (RFS) in patients with ACC treated with and without systemic (mitotane, cytotoxic chemotherapy) or localized (radiotherapy) non-surgical treatments. 86 studies met the inclusion criteria for the systematic review, and 62 for the meta-analysis. Data Extraction Two reviewers extracted data independently. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated for survival outcomes. Data Synthesis Mitotane significantly improves OS (aHR: 0.54; CI: 0.41-0.70) and RFS (aHR: 0.60; CI: 0.43-0.84), even in Stage I-III disease (OS aHR: 0.71; CI: 0.52-0.98; RFS aHR: 0.65; CI: 0.50-0.85). Radiotherapy showed a trend towards improved OS (aHR: 0.66; CI: 0.38-1.15) and RFS (aHR: 0.65; CI: 0.35-1.23), with significant benefits in Stage I-III (OS aHR: 0.68; CI: 0.50-0.93; RFS aHR: 0.71; CI: 0.63-0.81). The impact of cytotoxic chemotherapy on OS remains uncertain (aHR: 0.61; CI: 0.08-4.78). Conclusion Mitotane significantly improves survival outcomes in patients with ACC, while radiotherapy exhibits potential benefits, particularly in localized disease. Further research is needed to verify the efficacy of cytotoxic chemotherapy, and randomized controlled trials are required to provide robust evidence of different treatment approaches.