MOBILIZATION OF TUMOR-CELLS DURING BIOPSY IN AN INFANT WITH EWING SARCOMA

Ewing sarcoma and the closely related peripheral primitive neuroectode rmal tumour, recently referred to as Ewing tumour (ET), are characteri sed by unique gene rearrangements on chromosome 22. The breakpoints ha ve been cloned and shown to fuse the Ewing sarcoma gene to one of two closely related ETS proto-oncogens, FLI-1 or ERG, which reside on chro mosomes 11 and 21, respectively. The rearrangement results in the expr ession of specific hybrid transcripts which can be detected with high sensitivity by the reverse transcriptase polymerase chain reaction tec hnique (RT-PCR) in primary tumours, blood and bone marrow. We report o n a 7-month-old boy with a pelvic Ewing sarcoma in whom circulating tu mour cells were identified in the peripheral blood during open tumour biopsy by RT-PGR. However, before and 6 days after surgery no tumour c ells could be detected in the peripheral blood. Conclusion The applica tion of RT-PCR to monitor shedding of tumour during surgical intervent ion will help to evaluate if open biopsy potentially contributes to me tastatic tumour cell spread.