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Study of the MIB-1 Labeling Index as a Predictor of Tumor Progression in
Pilocytic Astrocytomas in Children and Adolescents
Daniel C. Bowers, Lynn Gargan, Payal
Kapur, Joan S. Reisch, Arlynn F. Mulne, Kenneth
N. Shapiro, Roy D. Elterman, Naomi J. Winick, Linda
R. Margraf
From the Departments of Pediatrics, Academic Computing
Services, and Pathology, University of Texas Southwestern Medical Center at
Dallas; and the Neuro-Oncology Program, Children’s Medical Center of Dallas,
Dallas, TX.
Address reprint requests to Daniel Bowers, MD, MC 9063,
Department of Pediatrics, University of Texas Southwestern Medical School at
Dallas, 5323 Harry Hines Blvd, Dallas, TX 75390-9063; email: daniel.bowers@
utsouthwestern.edu.
Purpose. The pilocytic astrocytoma (PA) is the most common
childhood brain tumor.
This report examines the MIB-1 labeling index
(LI) as a predictor of progression-free survival (PFS) among
childhood PAs.
Patients and Methods. Consecutive PAs were examined to
determine whether the MIB-1 LI was associated with tumor progression.
Other variables evaluated included tumor location, use of adjuvant therapy,
extent of resection, and age at diagnosis. Results. One hundred forty-one children were identified (mean
± SD age, 7.6 ± 4.7 years; range, 0.43 to 18.56 years); 118
children had adequate tissue for MIB-1 immunohistochemistry.
The
5-year PFS was 61.25%.
By log-rank analysis, an MIB-1 LI of more than
2.0 was associated with shortened PFS (P = .035).
Patients
with PAs who underwent complete surgical resection, had tumors
located in the cerebellum, and were treated with surgery only also
had more prolonged PFS (P = .001 for all).
Tumors in the optic
pathways were associated with a shorter PFS (P = .001).
Restricting the evaluation of MIB-1 LI to only incompletely resected
tumors revealed an insignificant trend of MIB-1 LI of more than 2.0
having a shortened PFS.
Multivariate analysis demonstrated completely
resected tumors and tumors located in the cerebellum as less likely
to progress (P = .001 and .019, respectively). Conclusion. Children with PAs with an MIB-1 LI of more than
2.0 have a shortened PFS.
PAs that are completely resected and are
located in the cerebellum have a prolonged PFS.
This initial study
suggests that the MIB-1 LI identifies a more aggressive subset of
PAs.
Further work should focus on elucidating features of pilocytic
astocytomas that will identify prospectively children at risk for
progression.
© 2003 American Society for
Clinical Oncology
Source: http://www.jco.org/cgi/content/abstract/21/15/2968
HTML Full Text: http://www.jco.org/cgi/content/full/21/15/2968
PDF Full Text: http://www.jco.org/cgi/reprint/21/15/2968
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