Residual nonfunctioning pituitary adenomas: prognostic value of MIB-1 labeling index for tumor progression.
OBJECTIVE
In residual nonfunctioning pituitary adenomas, reliable prognostic parameters indicating probability of tumor progression are needed. The Ki 67 expression/MIB-1 labeling index (LI) is considered to be a promising candidate factor. The aim in the present study was to analyze the clinical usefulness of MIB-1 LI for prognosis of tumor progression.


METHODS
The authors studied a cohort of 92 patients with nonfunctioning pituitary adenomas. Based on sequential postoperative MR images, patients were classified as tumor free (51 patients) or as harboring residual tumor (41 individuals). The residual tumor group was further subdivided in groups with stable residual tumors (14 patients) or progressive residual tumors (27 patients). The MIB-1 LI was assessed in tumor specimens obtained in all patients, and statistical comparisons of MIB-1 LI of the various subgroups were performed.


RESULTS
The authors found no significant difference of MIB-1 LI in the residual tumor group compared with the tumor-free group. However, MIB-1 LI was significantly higher in the progressive residual tumor group, compared with the stable residual tumor group. Additionally, the time period to second surgery was significantly shorter in residual adenomas showing an MIB-1 LI>3%.


CONCLUSIONS
The data indicate that MIB-1 LI in nonfunctioning pituitary adenomas is a clinically useful prognostic parameter indicating probability of progression of postoperative tumor remnants. The MIB-1 LI may be helpful in decisions of postoperative disease management (for example, frequency of radiographic intervals, planning for reoperation, radiotherapy, and/or radiosurgery).
Widhalm
Georg
G
Institute of Neurology, Department of Neurosurgery, Medical University Vienna, Vienna, Austria.
Wolfsberger
Stefan
S
Preusser
Matthias
M
Fischer
Ingeborg
I
Woehrer
Adelheid
A
Wunderer
Joerg
J
Hainfellner
Johannes A
JA
Knosp
Engelbert
E
D000236:Adenoma / Q000175:diagnosis* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000175:diagnosis; D010911:Pituitary Neoplasms / Q000175:diagnosis* / Q000601:surgery; D011184:Postoperative Period; D011379:Prognosis
D019394:Ki-67 Antigen