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Glioblastomas in the Older Old
B. K. Kleinschmidt-DeMasters, MD; K. O. Lillehei, MD; M.
Varella-Garcia, PhD
From the Departments of Pathology (Dr Kleinschmidt-DeMasters), Neurology (Dr
Kleinschmidt-DeMasters), Neurosurgery (Drs Kleinschmidt-DeMasters and
Lillehei), and Medicine (Medical Oncology) (Dr Varella-Garcia), University
of Colorado Health Sciences Center, Denver. Reprints: B. K.
Kleinschmidt-DeMasters, MD, Department of Pathology, University of
Colorado Health Sciences Center, 4200 E Ninth Ave, Denver, CO 80262
(E-mail: bk.demasters@uchsc.edu). Accepted December 10, 2004.
Context. Recent studies have identified fundamental biological differences
in the effects of epidermal growth factor receptor (EGFR) amplification on
survival in older versus younger patients with glioblastoma multiforme
(GBM).
Cell cycle labeling indices have also been found to be inordinately
high in older GBM patients and may contribute to the known adverse prognosis
in this cohort.
However, testing has not been conducted on significant
numbers of patients of very advanced age, in whom these features might be
expected to emerge as even more significant factors.
Objective. To assess
EGFR amplification status and MIB-1 indices in patients with GBM who are
older than 75 years.
Design. We identified 20 patients (female-male ratio,
11:9; 11 aged 75-79 years and 9 aged 80-87 years) and studied tumor tissue
samples with immunohistochemistry for cell cycle labeling index and by
fluorescence in situ hybridization for EGFR amplification.
Survival data
were obtained from the Colorado Tumor Registry.
Results. Mean MIB-1 index was
high (24.8%), but individual indices did not correlate with survival.
EGFR
amplification was detected in 25% of cases, with gain of chromosome 7 in all
but one of the remaining patients.
Ninety-five percent of patients
manifested EGFR amplification and/or polysomy of chromosome 7.
Heterogeneity
was found within a given tumor, with 10% to 60% of cells showing gain of
chromosome 7.
Overall patient survival was poor (mean, 4.6 months), but was
significantly longer in those with EGFR gene amplification (mean, 8.3
months; median, 10.5 months) versus those without (mean, 3.2 months; median,
2.0 months) (P = .04).
Conclusion. The presence of EGFR amplification is a
significant predictor of survival time in older old patients.
Presented in abstract form at the United States and Canadian
Academy of Pathology meeting, Vancouver, BC, February 2004.
© Copyright by College of American
Pathologists 2005
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