Helsinki score—a novel model for prediction of metastases in adrenocortical carcinomas

Abstract

Histopathologic diagnosis of adrenocortical tumors is based on adverse features that indicate malignant potential. Proliferation index has served as a supplemental tool in assessing the malignant potential of adrenocortical tumors. None of the current histologic classification systems can sufficiently accurately predict tumors' metastatic potential. We studied 177 consecutive adult patients with primary adrenocortical tumors operated on at Helsinki University Central Hospital between 1990 and 2003, all patients with a minimum follow-up of 5 years. We determined for each tumor the Weiss score and the Weiss revisited score by Aubert. Proliferation index was measured by computer-assisted image analysis. Each of the 9 Weiss criteria and the proliferation index were then used to establish a scoring system to predict the metastatic potential of adrenocortical tumors. Use of stepwise regression analysis led us to propose a calculation: 3 × mitotic rate (>5/50 high-power fields) + 5 × presence of necrosis + proliferation index in the most proliferative area of the tumor. Using a cutoff value of 8.5, the new scoring system was able to diagnose metastatic adrenocortical carcinoma with 100% sensitivity (confidence interval [CI], 76.8%-100%) and 99.4% specificity (CI, 96.6%-100%). The corresponding sensitivity of the Weiss system was 100% (CI, 76.8%-100%), and specificity, 90.2% (CI, 84.6%-94.3%), with sensitivity of the Weiss revisited system at 100% (CI, 76.8%-100%) and specificity at 96.9% (CI, 93.0%-99.0%). The new Helsinki score thus was accurate in predicting the metastatic potential of adrenocortical tumors.