Implications of Conversion during Attempted Minimally Invasive Adrenalectomy for Adrenocortical Carcinoma

Background: Although advocated by some, minimally invasive adrenalectomy (MIA) for adrenocortical carcinoma (ACC) is controversial. Moreover, the oncologic implications for patients requiring conversion to an open procedure during attempted MIA for ACC are not extensively reported. Patients and Methods: The National Cancer Database was queried for patients undergoing resection for ACC. Overall survival (OS) for patients undergoing successful MIA was compared with those requiring conversion, and additionally evaluated with a multivariable Cox regression analysis including other factors associated with OS.After propensity matching, those experiencing conversion were further compared with patients who underwent planned open resection. Results: Among 196 patients undergoing attempted MIA for ACC, 38 (19.4%) required conversion. Independent of 90-day postoperative mortality, conversion was associated with significantly reduced OS compared with successful MIA (median 27.9 months versus not reached, p = 0.002). Even for tumors confined to the adrenal, conversion was associated with worse median OS compared with successful MIA (median 34.2 months versus not reached, p = 0.003). After propensity matching for clinicopathologic covariates to establish well-balanced cohorts (N = 38 per group), patients requiring conversion during MIA had significantly worse OS than those having planned open resection (27.9 months versus 50.5 months, p = 0.020). On multivariable analysis for predictors of OS, conversion during MIA (HR 2.32, p = 0.003) was independently associated with mortality. Conclusions: ACC is a rare tumor for which adequate oncologic resection is the only chance for cure. Given the relatively high rate of conversion and its associated inferior survival, open resection should be considered standard of care for known or suspected ACC.