Combined 1p/19q loss in oligodendroglial tumors: predictive or prognostic biomarker?
OBJECTIVE
The combined loss of genetic material on chromosomes 1p and 19q is strongly associated with favorable outcome in patients with WHO grade 3 anaplastic oligodendroglial tumors. The prognostic value of 1p/19q loss in WHO grade 2 oligodendroglial tumors is less well defined. Importantly, the possible effect of combined 1p/19q loss has not been studied in patients who were not treated with radiotherapy or chemotherapy.


METHODS
Seventy-six patients with oligodendroglioma (n = 33), oligoastrocytoma (n = 30), anaplastic oligodendroglioma (n = 6), or anaplastic oligoastrocytoma (n = 7) were identified who had not received radiotherapy or chemotherapy after their first operation until the end of follow-up or until the first progression and had tissue for 1p/19q status available. 1p/19q status was assessed by multiplex ligation-dependent probe amplification.


RESULTS
After a median follow-up of 3.8 years, progressive disease was documented in 34 patients. The estimated median progression-free survival was 4.6 years. Fifty-eight of the 76 patients had a combined loss of 1p and 19q. The absence or presence of combined 1p/19q loss was not prognostic for progression-free survival using multivariate adjustment for histology, extent of resection, and gender.


CONCLUSIONS
Combined 1p/19q loss is not a sensitive prognostic biomarker in patients with oligodendroglial tumors who do not receive radiotherapy or chemotherapy. The gene products lost as a consequence of this codeletion may include mediators of resistance to genotoxic therapies. Alternatively, 1p/19q loss might be an early oncogenic lesion promoting the formation of glial neoplasms, which retain high sensitivity to genotoxic stress.
Department of General Neurology, University of Tübingen, Tübingen, Germany. michael.weller@uni-tuebingen.de
Michael
M
Weller
Hilmar
H
Berger
Christian
C
Hartmann
Johannes
J
Schramm
Manfred
M
Westphal
Matthias
M
Simon
Roland
R
Goldbrunner
Dietmar
D
Krex
Joachim P
JP
Steinbach
Christoph B
CB
Ostertag
Markus
M
Loeffler
Torsten
T
Pietsch
Andreas
A
von Deimling
D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics / Q000473:pathology; D014408:Biomarkers, Tumor / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics*; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009837:Oligodendroglioma / Q000235:genetics* / Q000473:pathology; D011237:Predictive Value of Tests
D014408:Biomarkers, Tumor