Comparison between surgery and thermal ablation for adrenal metastases: a retrospective study.

PURPOSE: To retrospectively compare the efficacy and safety of surgical resection (SR) and thermal ablation for the treatment of adrenal metastases. METHODS: From January 2008 to December 2018, 133 patients with adrenal metastases who underwent SR (n = 76) or thermal ablation (n = 57) were enrolled. The mean tumor size was 58.00 ± 10.65 mm (22-80 mm) in the SR group and 58.03 ± 12.76 mm (34-89 mm) in the thermal ablation group. Local progression-free survival (LPFS) and safety were compared between the two groups using the Kaplan-Meier method and log-rank tests. Cox proportional hazard regression models were used to evaluate the prognostic factors of LPFS. Complications, hospitalization days, and blood loss were also assessed. RESULTS: The median follow-up was 29.0 months (range, 20.4-37.6 months). No treatment-related mortality was observed. The 1-, 3- and 5-year LPFS rates were 74.0%, 62.8%, and 31.4% in the SR group and 72.8%, 68.7%, and 51.5% in the ablation group, with the median LPFS of 41.5 months (95% CI: 9.3-23.4 months) vs. 47.9 months (95% CI 20.6-75.8 months), respectively (p = 0.784). Tumor size ≥3 cm was the only significant risk factor for LPFS (p = 0.031). The ablation group was superior to the SR group with a lower major complication rate (4.1% vs. 14.5%, p = 0.03), less blood loss (1 ml vs. 100 ml, p < 0.001), and a shorter hospital stay (2 d vs. 6 d, p < 0.001). CONCLUSION: Thermal ablation provided a similar LPFS and less comorbidities than SR, indicating that it is an effective and safe treatment for adrenal metastases.