Validation of the prognostic role of the "Helsinki Score" in 225 cases of adrenocortical carcinoma

Adrenocortical carcinoma patient prognosis is extremely variable and poorly predictable. The newly introduced Helsinki Score is the first so far proposed diagnostic and prognostic system based on the combined evaluation of morphological (mitoses and necrosis) and immunohistochemical (Ki-67) parameters. The aim of the study was to validate the prognostic role of the Helsinki Score for adrenocortical carcinoma characterization. Thus, 225 adrenocortical carcinomas were reclassified using the Weiss Score and the Helsinki Score (3× mitotic count +5× necrosis + Ki-67 index). At univariate analysis, statistically significant prognostic values were observed at the log-rank test for mitotic count (cut-off values: <6 and ≥55; P<.0001), Ki-67 (cut-off values: <20 and ≥50; P<.0001), Weiss Score (cut-off values: <5 and ≥8; P<.0001), Helsinki Score (cut-off values: <13 and ≥19; P<.0001), histological variant (conventional vs oncocytic; P=.009), necrosis (P=.001) and stage (P=.005). Cox multivariate analysis using a backward stepwise selection method retained only Helsinki Score and Weiss Score as predictors of poor prognosis (P<.0001 and P=.0005, respectively). Helsinki Score (with a threshold of 28.5 points; AUC=0.729, 95% confidence interval [CI]=0.66-0.79) and Ki-67 (with a threshold of 20.5%; AUC=0.727, 95% CI=0.66-0.79) showed the best and equivalent areas under the curve (AUC) predicting disease-related deaths determined using receiver-operating characteristic statistics. In conclusion, the Helsinki Score is a valuable system to predict prognosis in adrenocortical carcinoma, outperforming the currently established prognostic parameters.