Prognostic significance of standardized AgNOR analysis and Ki-67 immunostaining in gastrointestinal stromal tumors

Abstract OBJECTIVE: To evaluate the prognostic utility of argyrophilic nucleolar organizer region (AgNOR) protein parameters and Ki-67-immunostained growth fraction (Ki-67 labelling index) and to correlate AgNORs with Ki-67 LI and the main clinicopathologic parameters in gastrointestinal stromal tumors (GISTs). STUDY DESIGN: On 55 patients with surgically excised GISTs, visualization and quantification of AgNORs were performed as specified in the guidelines of the Committee on AgNOR Quantification. RESULTS: AgNOR protein area (NORA) ≥5.28 μm2 was statistically associated with mitotic rate ≥5x10 high-power fields (hpfs) (P <.001) and presence of necrosis (P <.001); Ki-67 LI ≥9.69% was signif…