Minimally Invasive Adrenalectomy for Adrenocortical Carcinoma: Five-Year Trends and Predictors of Conversion.

Background: Adrenocortical carcinoma (ACC) is rare but often fatal. Surgery offers the only chance of cure. As minimally invasive (MI) procedures for cancer become common, their role for ACC is still debated. We reviewed usage of MI approaches for ACC over time and risk factors for conversion using a large national database.
Methods: ACC patients with localized disease were identified in the National Cancer Data Base from 2010 to 2014. A retrospective review examined trends in the surgical approach over time. Patient demographics, surgical approach, and tumor characteristics between MI, open, and converted procedures were compared.
Results: 588 patients underwent adrenalectomy for ACC, of which 200 were minimally invasive. From 2010 to 2014, MI operations increased from 26 to 44% with robotic procedures increasing from 5 to 16%. The use of MI operations compared to open was not different based on facility type (p = 0.40) or location (p = 0.63). MI tumors were more likely to be confined to the adrenal (p < 0.001) but final margin status was not different (p = 0.56). Conversion was performed in 38/200 (19%). Average tumor size was 10.2 cm in the converted group compared to 8.6 cm in the MI group (p = 0.09). There was no difference in extent of disease (p = 0.33), margin status (p = 0.12), or lymphovascular invasion (p = 0.59) between MI and converted procedures. Tumor size > 5 cm was the only significant predictor of conversion (p = 0.04). No patients with pathologic stage I disease required conversion (0/19).
Conclusions: The frequency of MI approaches for ACC is increasing. In the final year of the study, 44% of adrenalectomies were MI. Size > 5 cm was the only significant predictor of conversion.