Major prognostic role of Ki67 in localized adrenocortical carcinoma after complete resection

Abstract

Background: Recurrence of adrenocortical carcinoma (ACC) even after complete (R0) resection occurs frequently. Objective: The aim of this study was to identify markers with prognostic value for patients in this clinical setting. Design, Setting, and Participants: From the German ACC registry, 319 patients with the European Network for the Study of Adrenal Tumors stage I-III were identified. As an independent validation cohort, 250 patients from three European countries were included. Outcome Measurements and Statistical Analysis: Clinical, histological, and immunohistochemical markers were correlated with recurrence-free (RFS) and overall survival (OS). Results: Although univariable analysis within the German cohort suggested several factors with potential prognostic power, upon multivariable adjustment only a few including age, tumor size, venous tumor thrombus (VTT), and the proliferation marker Ki67 retained significance. Among these, Ki67 provided the single best prognostic value for RFS (hazard ratio [HR] for recurrence, 1.042 per 1% increase; P <.0001) and OS (HR for death, 1.051; P <.0001) which was confirmed in the validation cohort. Accordingly, clinical outcome differed significantly between patients with Ki67