Impact of postoperative radiotherapy on the outcomes of resected adrenocortical carcinoma-a real-world, population-based study

Objective To assess the impact of postoperative radiotherapy on the outcomes of resected adrenocortical carcinoma in a real-world setting. Methods The Surveillance, Epidemiology, and End Results Research Plus database was accessed, and patients with resected non-metastatic adrenocortical carcinoma diagnosed 2010-2015 were reviewed. Kaplan-Meier estimates and log-rank testing were used to examine the impact of postoperative radiotherapy on overall and cancer-specific survival. Multivariable Cox regression analysis was used to explore factors associated with overall and cancer-specific survival. Results A total of 294 patients were included in the final analysis, including 60 patients (20.4%) who received postoperative radiotherapy. Using Kaplan-Meier estimates, individuals who received postoperative radiotherapy have better overall survival (P = 0.002). Multivariable cox regression analysis showed that the following factors were associated with worse overall survival: older age (HR: 1.01; 95% CI: 1.00-1.03), male sex (HR for female sex versus male sex: 0.61; 95% CI: 0.43-0.85), and non-receipt of postoperative radiation therapy (HR: 2.29; 95% CI: 1.38-3.77). Systemic therapy was not associated with differences in overall survival (HR: 0.77; 95% CI: 0.54-1.10). Likewise, the following factors were associated with worse cancer-specific survival: male sex (HR for female sex versus male sex: 0.60; 95% CI: 0.41-0.88), non-receipt of postoperative radiation therapy (HR: 2.17; 95% CI: 1.27-3.70), and receipt of perioperative systemic therapy (HR: 0.67; 95% CI: 0.45-0.99). Conclusion Postoperative radiotherapy following resection of adrenocortical carcinoma is associated with better overall and cancer-specific survival.