Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Oct;39(6):706-17.
doi: 10.1111/nan.12031.

1p/19q testing has no significance in the workup of glioblastomas

K H Clark  1 , J L Villano, M N Nikiforova, R L Hamilton, C Horbinski
Affiliations

1p/19q testing has no significance in the workup of glioblastomas

K H Clark et al. Neuropathol Appl Neurobiol. 2013 Oct.

Abstract

Aims: To determine whether testing for isolated 1p or 19q losses, or as a codeletion, has any significance in the workup of glioblastomas (GBMs).

Methods: Upfront 1p/19q testing by fluorescence in situ hybridization (FISH) and/or polymerase chain reaction (PCR)-based loss of heterozygosity (LOH) was done in 491 gliomas that were histologically diagnosed as GBMs. Outcomes were determined and measured against 1p/19q results.

Results: Twenty-eight showed apparent 1p/19q codeletion by either FISH and/or PCR-based LOH, but only 1/26 showed codeletion by both tests. Over 90% of tumours with apparent codeletion by either FISH or LOH also had 10q LOH and/or EGFR amplification, features inversely related to true whole-arm 1p/19q codeletion. Furthermore, only 1/28 tumours demonstrated an R132H IDH1 mutation. Neither 1p/19q codeletion by FISH nor LOH had an impact on GBM survival. Isolated losses of 1p or 19q also had no impact on survival.

Conclusions: These data suggest that (i) 1p/19q testing is not useful on gliomas that are histologically GBMs; (ii) codeletion testing should be reserved only for cases with compatible morphology; and (iii) EGFR, 10q, and IDH1 testing can help act as safeguards against a false-positive 1p/19q result.

Keywords: 1p/19q; FISH; LOH; glioblastoma.

PubMed Disclaimer

Figures

Figure 1
Figure 1
GBMs with false 1p/19q codeletion by FISH. Despite strong astrocytic morphology, all four cases of GBM showed 1p/19q codeletion by FISH (case numbers correspond to Table 2). However, none were codeleted by PCR-based LOH analysis and all had 10q LOH. Case 3 (A, B) also had EGFR amplification. None of the four patients survived beyond 10 months after initial surgery. FISH, fluorescence in situ hybridization; LOH, loss of heterozygosity; GBM, glioblastoma; PCR, polymerase chain reaction.
Figure 2
Figure 2
Glioblastomas with false 1p/19q codeletion by LOH. Analogous to Figure 1, these four histologically unequivocal GBMs showed 1p/19q codeletion by LOH (case numbers correspond to Table 2). Only case 18 appeared codeleted by FISH and all had 10q LOH. Case 22 (E, F) also had EGFR amplification. None of the four patients survived beyond 15 months after initial surgery. FISH, fluorescence in situ hybridization; LOH, loss of heterozygosity; GBM, glioblastoma.
Figure 3
Figure 3
1p/19q data lacks prognostic significance in histological GBMs. On univariate analysis, neither 1p/19q FISH (A) nor PCR-based LOH data (B) had any relevance concerning overall survival. FISH, fluorescence in situ hybridization; LOH, loss of heterozygosity; GBM, glioblastoma; PCR, polymerase chain reaction.
See this image and copyright information in PMC

References

    1. Reifenberger J, Reifenberger G, Liu L, James CD, Wechsler W, Collins VP. Molecular genetic analysis of oligodendroglial tumors shows preferential allelic deletions on 19q and 1p. Am J Pathol. 1994;145:1175–90. - PMC - PubMed
    1. Kraus JA, Koopmann J, Kaskel P, Maintz D, Brandner S, Schramm J, Louis DN, Wiestler OD, von Deimling A. Shared allelic losses on chromosomes 1p and 19q suggest a common origin of oligodendroglioma and oligoastrocytoma. J Neuropathol Exp Neurol. 1995;54:91–5. - PubMed
    1. Jenkins RB, Blair H, Ballman KV, Giannini C, Arusell RM, Law M, Flynn H, Passe S, Felten S, Brown PD, Shaw EG, Buckner JC. A t(1;19)(q10;p10) mediates the combined deletions of 1p and 19q and predicts a better prognosis of patients with oligodendroglioma. Cancer Res. 2006;66:9852–61. - PubMed
    1. Griffin CA, Burger P, Morsberger L, Yonescu R, Swierczynski S, Weingart JD, Murphy KM. Identification of der(1;19)(q10;p10) in five oligodendrogliomas suggests mechanism of concurrent 1p and 19q loss. J Neuropathol Exp Neurol. 2006;65:988–94. - PubMed
    1. Jeuken JW, von Deimling A, Wesseling P. Molecular pathogenesis of oligodendroglial tumors. J Neurooncol. 2004;70:161–81. - PubMed

Publication types