INCIDENCE OF BONE-MARROW INVOLVEMENT IN EWINGS-SARCOMA - VALUE OF EXTENSIVE INVESTIGATION OF THE BONE-MARROW

Purpose: Bone marrow (BM) status is a critical matter when intensified chemotherapy with bone marrow rescue is proposed to improve the survi val of patients with poor prognosis Ewing's sarcoma (ES): metastatic o r relapsing disease. A systematic bone marrow investigation was perfor med in all the patients with newly diagnosed ES or relapsing ES to ass ess their BM status. Patients and Methods:From January 1985 to Februar y 1989, 59 untreated patients and five patients at the time of relapse had a bone marrow investigation under general anesthesia: two BM biop sies and two BM aspirates until May 1986, then two BM biopsies and 10 BM aspirates. The classical method of smearing each BM aspirate was co mpared to cytocentrifugation of the pool of BM samples after gradient density separation. Results: The BM was involved in 13 of 59 untreated patients. BM was the single site of metastatic spread in only one pat ient but was involved in 52% of the patients with metastatic disease a l other sites. This involvement was focal in several patients and freq uent discrepancies were noted between the aspirates and biopsies at th e various sites explored. The number of positive cases of BM involveme nt discovered by the two methods is somewhat limited. However prelimin ary results indicate a superior rate of positive smears with the pool technique which did however fail to detect involvement in some cases. Conclusions: The present study indicates that 1) BM involvement is a f requent event in metastatic ES (52%); 2) is often multifocal and there fore requires extensive BM investigation; and 3) further investigation of the pool technique to facilitate the BM screening is warranted. (C ) 1995 Wiley-Liss, Inc.