Presence of tumor cells in bone marrow but not in blood is associated with adverse prognosis in patients with Ewing's tumor. Société Française d'Oncologie Pédiatrique.
OBJECTIVE
Gene fusions that result from the chromosome translocations observed in Ewing's tumor (ET) provide tumor-specific markers that can be used to detect the presence of tumor cells in peripheral blood (PB), bone marrow (BM), and stem cell collection (SCC). These markers were used to evaluate, at diagnosis, a series of 67 ET patients.


METHODS
RNA was extracted from nucleated cells from PB and BM and a nested reverse-transcriptase polymerase chain reaction (RT-PCR) was performed to search for EWS-FLI-1 or EWS-ERG fusion transcripts that resulted from the t(11;22) or t(21;22) translocations, respectively.


RESULTS
At diagnosis, 16 of 62 (26%) patients had circulating tumor cells. This was not correlated with any clinical parameter. In contrast, Ewing's cells were detected by RT-PCR in BM in 14 of 43 (33%) patients and were associated with the presence of clinically detectable metastases and a statistically significant unfavorable outcome in univariate analysis. There was no correlation between the RT-PCR results in PB and in BM.


CONCLUSIONS
These results suggested that the monitoring of BM but not of PB by RT-PCR might constitute an important criterion for the staging, at diagnosis, of patients with ET. Further studies should appreciate the relationship or independence of this marker toward other classical prognostic factors in ET, particularly to the presence of clinically detectable metastases.
Fagnou
C
C
Département d'Oncologie Pédiatrique, Institut Curie, Paris, France.
Michon
J
J
Peter
M
M
Bernoux
A
A
Oberlin
O
O
Zucker
J M
JM
Magdelenat
H
H
Delattre
O
O
D000293:Adolescent; D000328:Adult; D019677:Artificial Gene Fusion; D001853:Bone Marrow / Q000473:pathology*; D001859:Bone Neoplasms / Q000097:blood / Q000235:genetics / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D006801:Humans; D007223:Infant; D009360:Neoplastic Cells, Circulating; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012512:Sarcoma, Ewing / Q000097:blood / Q000235:genetics / Q000473:pathology*; D014178:Translocation, Genetic