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.
Weller
Michael
M
Department of General Neurology, University of Tübingen, Tübingen, Germany. michael.weller@uni-tuebingen.de
Berger
Hilmar
H
Hartmann
Christian
C
Schramm
Johannes
J
Westphal
Manfred
M
Simon
Matthias
M
Goldbrunner
Roland
R
Krex
Dietmar
D
Steinbach
Joachim P
JP
Ostertag
Christoph B
CB
Loeffler
Markus
M
Pietsch
Torsten
T
von Deimling
Andreas
A
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