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


METHODS
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) > or = 5.28 microns 2 was statistically associated with mitotic rate > or = 5 x 10 high-power fields (hpfs) (P < .001) and presence of necrosis (P < .001); Ki-67 LI > or = 9.69% was significantly associated with mitotic rate > or = 5 x 10 hpfs (P < .001), size > or = 5 cm (P = .033) and presence of necrosis (P < .001). Ki-67 LI and NORA strongly correlated. Preliminary Kaplan-Meier survival analysis showed that an increased value of NORA, Ki-67 LI, mitotic rate, tumor size and presence of necrosis had a negative influence on patient survival. Multivariate regression analysis showed that only NORA and Ki-67 LI were independent parameters in predicting the clinical outcome for patients with GISTs. Mitotic rate and necrosis remained as independent prognostic factors when NORA and Ki-67 LI were not allowed to enter in models.


CONCLUSIONS
AgNOR protein quantity, as determined by image cytometry, and Ki-67 immunostaining seem to represent reliable predictive parameters in GISTs and are independent of mitotic rate, tumor dimension and necrosis.
Rodolico
Vito
V
Institute of Pathological Anatomy and Histology, University of Palermo, Palermo, Italy. rodolicovti@hotmail.com
Martorana
Anna
A
Gulotta
Gaspare
G
Diana
Giuseppe
G
Leonardi
Vincenza
V
Cocorullo
Gianfranco
G
Ajello
Francesca
F
D000328:Adult; D000368:Aged; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D019044:Image Cytometry / Q000592:standards; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009697:Nucleolus Organizer Region / Q000737:chemistry*; D011237:Predictive Value of Tests; D011379:Prognosis; D017154:Stromal Cells / Q000737:chemistry
D019394:Ki-67 Antigen