DNA AND RNA-CONTENT ANALYSIS BY FLOW-CYTOMETRY IN THE PATHOBIOLOGIC ASSESSMENT OF BONE-TUMORS

Studies of simultaneous DNA and RNA contents by now cytometry in hemat ologic and some solid neoplasms have been shown to provide information that may be useful in the pathobiological evaluation of these neoplas ms, We contend that similar analysis may be equally valuable in assess ing bone tumors. Our data revealed significant statistical differences in DNA ploidy and proliferative fraction between benign and malignant bone neoplasms. Benign tumors manifested predominantly DNA diploidy a nd low proliferative activity, whereas the majority of malignant tumor s were DNA. aneuploid and showed high proliferation rate. No significa nt difference in the RNA content between different histopathologic cat egories was found. We observed, however, a distinct and consistently h igh RNA content pattern in giant cell tumors, aneurysmal bone cysts, a nd chondroblastomas that may be useful in their differential diagnosis , Analysis of different prognostic factors in malignant tumors indicat ed that histologic grade and DNA content are a significant prognostic factors, Further analysis of malignant tumors showed that a correlatio n between the proliferative activity and the clinical outcome in the l ow grade category and between RNA content and patients' survival in os teosarcomas, Our study also showed that preoperative treatment signifi cantly impacted on the extent of the proliferative fraction in maligna nt tumors. We conclude that DNA/RNA analysis of bone tumor may assist in: (1) the differential diagnosis of certain bone tumors, (2) evaluat ion of treatment response, and (3) the biological assessment of osteos arcomas. (C) 1995 Wiley-Liss, Inc.