Minichromosome Maintenance Proteins MCM-3, MCM-5, MCM-7, and Ki-67 as Proliferative Markers in Adrenocortical Tumors

BACKGROUND/AIM: Morphological features, combined with Ki-67 proliferative index, remain the standard for discriminating benign and malignant adrenocortical tumors. The aim of this study was to evaluate the role of minichromosome maintenance proteins MCM-3, MCM-5, MCM-7, and Ki-67 as proliferative markers in adrenocortical tumors. MATERIALS AND METHODS: Specimens of 81 adrenocortical adenomas and 3 adrenocortical carcinomas were stained with antibodies against MCM-3, 5, 7 and Ki-67. RESULTS: Malignant tumors were characterized by a greater size (p=0.017), volume (p=0.017), and higher levels of Ki-67 (p=0.005), MCM-3 (p=0.005), MCM-7 (p=0.008), but not MCM-5 (p=0.069). The markers' levels were independent from the tumors' size and volume, the patient's age and hormonal status. ROC curves showed Ki-67 (AUC 0.984), MCM-3 (AUC 0.984), and MCM-7 (AUC 0.950), but not MCM-5 (AUC 0.820) to be reliable markers. CONCLUSION: Ki-67, MCM-3, and MCM-7, but not MCM-5 are reliable proliferative and diagnostic markers in discerning benign and malignant adrenocortical tumors.