Abstract
Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET) is a diagnostically challenging malignant round cell tumor with signature translocations involving the EWS gene. These translocations are detectable with both reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) in formalin-fixed paraffin-embedded tissue. However, RT-PCR is less sensitive in formalin-fixed paraffin-embedded than frozen tissue. Similarly, commercial FISH probes have recently become available, but have yet to be rigorously tested in the clinical setting. Therefore, we have compared RT-PCR with FISH using 'home brew' fusion probes for Ewing sarcoma (EWS)-FLI1 and a commercial EWS break apart probe set in 67 archival round cell tumors, including 27 EWS/PNETs. Sensitivities and specificities for both FISH assays were 91 and 100%, respectively, whereas RT-PCR had a sensitivity of 54% and a specificity of 85%. The break apart strategy was easier to interpret than probe fusion approach. We conclude that FISH is a more sensitive and reliable ancillary technique than RT-PCR for the diagnosis of EWS/PNET in formalin-fixed paraffin-embedded tissue, although the latter provides additional information regarding fusion transcript subtype and prognosis. The commercial break apart probe set is both readily available and easy to interpret, making it particularly attractive. Nonetheless, complex round cell tumors often benefit from molecular testing with multiple methods.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1-8 |
| Number of pages | 8 |
| Journal | Modern Pathology |
| Volume | 19 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2006 |
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Keywords
- Ewing sarcoma
- FISH
- Fusion transcript
- Molecular diagnostics
- Primitive neuroectodermal tumor
- RT-PCR
- Translocation
ASJC Scopus subject areas
- Pathology and Forensic Medicine
Cite this
Molecular diagnosis of Ewing sarcoma/primitive neuroectodermal tumor in routinely processed tissue : A comparison of two FISH strategies and RT-PCR in malignant round cell tumors. / Bridge, Robert S.; Rajaram, Veena; Dehner, Louis P.; Pfeifer, John D.; Perry, Arie.
In: Modern Pathology, Vol. 19, No. 1, 01.2006, p. 1-8.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Molecular diagnosis of Ewing sarcoma/primitive neuroectodermal tumor in routinely processed tissue
T2 - A comparison of two FISH strategies and RT-PCR in malignant round cell tumors
AU - Bridge, Robert S.
AU - Rajaram, Veena
AU - Dehner, Louis P.
AU - Pfeifer, John D.
AU - Perry, Arie
PY - 2006/1
Y1 - 2006/1
N2 - Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET) is a diagnostically challenging malignant round cell tumor with signature translocations involving the EWS gene. These translocations are detectable with both reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) in formalin-fixed paraffin-embedded tissue. However, RT-PCR is less sensitive in formalin-fixed paraffin-embedded than frozen tissue. Similarly, commercial FISH probes have recently become available, but have yet to be rigorously tested in the clinical setting. Therefore, we have compared RT-PCR with FISH using 'home brew' fusion probes for Ewing sarcoma (EWS)-FLI1 and a commercial EWS break apart probe set in 67 archival round cell tumors, including 27 EWS/PNETs. Sensitivities and specificities for both FISH assays were 91 and 100%, respectively, whereas RT-PCR had a sensitivity of 54% and a specificity of 85%. The break apart strategy was easier to interpret than probe fusion approach. We conclude that FISH is a more sensitive and reliable ancillary technique than RT-PCR for the diagnosis of EWS/PNET in formalin-fixed paraffin-embedded tissue, although the latter provides additional information regarding fusion transcript subtype and prognosis. The commercial break apart probe set is both readily available and easy to interpret, making it particularly attractive. Nonetheless, complex round cell tumors often benefit from molecular testing with multiple methods.
AB - Ewing sarcoma/primitive neuroectodermal tumor (EWS/PNET) is a diagnostically challenging malignant round cell tumor with signature translocations involving the EWS gene. These translocations are detectable with both reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) in formalin-fixed paraffin-embedded tissue. However, RT-PCR is less sensitive in formalin-fixed paraffin-embedded than frozen tissue. Similarly, commercial FISH probes have recently become available, but have yet to be rigorously tested in the clinical setting. Therefore, we have compared RT-PCR with FISH using 'home brew' fusion probes for Ewing sarcoma (EWS)-FLI1 and a commercial EWS break apart probe set in 67 archival round cell tumors, including 27 EWS/PNETs. Sensitivities and specificities for both FISH assays were 91 and 100%, respectively, whereas RT-PCR had a sensitivity of 54% and a specificity of 85%. The break apart strategy was easier to interpret than probe fusion approach. We conclude that FISH is a more sensitive and reliable ancillary technique than RT-PCR for the diagnosis of EWS/PNET in formalin-fixed paraffin-embedded tissue, although the latter provides additional information regarding fusion transcript subtype and prognosis. The commercial break apart probe set is both readily available and easy to interpret, making it particularly attractive. Nonetheless, complex round cell tumors often benefit from molecular testing with multiple methods.
KW - Ewing sarcoma
KW - FISH
KW - Fusion transcript
KW - Molecular diagnostics
KW - Primitive neuroectodermal tumor
KW - RT-PCR
KW - Translocation
UR - http://www.scopus.com/inward/record.url?scp=32844474047&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=32844474047&partnerID=8YFLogxK
U2 - 10.1038/modpathol.3800486
DO - 10.1038/modpathol.3800486
M3 - Article
C2 - 16258512
AN - SCOPUS:32844474047
VL - 19
SP - 1
EP - 8
JO - Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
JF - Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc
SN - 0893-3952
IS - 1
ER -