Diagnostic and prognostic utility of SF-1 in adrenal cortical tumours

Superior imaging techniques have increased the recognition of adrenal pathology. Distinguishing benign from malignant adrenocortical tumors is not always easy. Several criteria and immunohistochemical markers have been discovered which help to differentiate between adrenocortical adenoma (ACA) and adrenocortical carcinoma (ACC). Our aim here was to evaluate the diagnostic and prognostic role of steroidogenic factor-1 (SF-1) in adult adrenocortical tumors (ACT) diagnosed using the Weiss criteria. In this cohort, we have also analyzed Ki67 and p53 expression and the extent of agreement between SF-1 and Ki-67.

This was a retrospective, observational study comprising 24 cases of adult ACT over 10 years. Immunohistochemical staining for SF-1, Ki67, and p53 was done in all the cases, and the results correlated with the morphological diagnosis made using Weiss criteria.

SF-1 was 100% sensitive and 80% specific as a marker of malignancy. Increased SF-1 expression correlated with worse survival. There was a moderate degree of agreement between Ki-67 labeling-index and SF-1 as a marker of malignancy with the kappa coefficient being 0.75. The sensitivity of p53 was lower than Ki67 in diagnosing ACC.

In adult ACTs, SF-1 has diagnostic significance and prognostic implication. SF-1 is a crucial, dosage-dependent survival factor in ACC. There is a moderate extent of agreement between Ki-67 and SF-1 as a marker of malignancy.