Prognostic Value of Ki-67 Labeling Index and Postoperative Radiotherapy in WHO Grade II Meningioma.
OBJECTIVE
This study was performed to determine the clinical significance of the Ki-67 labeling index (LI) for local control (LC) in patients with World Health Organization (WHO) grade II meningioma. We also tried to discern the effect of postoperative radiotherapy (PORT) on LC depending upon the Ki-67 LI value.


METHODS
The medical records and values of Ki-67 LIs were retrospectively reviewed for 50 patients who underwent surgical resection of intracranial WHO grade II meningiomas at Samsung Medical Center from May 2001 to December 2012. Forty-three patients (86%) were treated with immediate PORT. The median total radiation dose was 60 Gy (range, 54 to 60 Gy).


RESULTS
The median follow-up was 47.4 months. The mean Ki-67 LI was 13% (range, 1% to 47%). Twelve patients (24.0%) showed local failure, and 8 patients (16.0%) experienced local failure even after PORT. The mean Ki-67 LI was 15% in patients with local failure (n=12) and 12% in patients without local failure (n=38). The 3-year actuarial LC was 80.5%. The 3-year overall survival was 89.5%. Ki-67 LI>13% and PORT were significant prognostic factors for LC (P=0.015 and 0.009, respectively). In patients with Ki-67 LI>13% (n=17), PORT (n=14) improved LC (P<0.001). However, PORT (n=29) did not affect LC (P=0.412) for patients with Ki-67 LI≤13% (n=33).


CONCLUSIONS
Ki-67 LI can be a useful prognostic factor for LC in WHO grade II meningioma. In patients with Ki-67 LI>13%, PORT should be recommended to improve LC.
Departments of Radiation Oncology.|Department of Radiation Oncology, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
Yunseon
Y
Choi
Departments of Radiation Oncology.
Do Hoon
DH
Lim
Departments of Radiation Oncology.
Jeong Il
JI
Yu
Neurosurgery.
Kyungil
K
Jo
Neurosurgery.
Do-Hyun
DH
Nam
Neurosurgery.
Ho Jun
HJ
Seol
Neurosurgery.
Jung-Il
JI
Lee
Neurosurgery.
Doo-Sik
DS
Kong
Pathology, Samsung Medical Center.
Yeon-Lim
YL
Suh
Department of Radiation Oncology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul.
Heerim
H
Nam
D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D015331:Cohort Studies; D016208:Databases, Factual; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D008579:Meningioma / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D019635:Neurosurgical Procedures / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen