Prediction of Clinical Course and Biologic Behavior of the Bone Giantcell Tumor Using Bax and Bcl-2 Markers

Background and objectives: giant cell tumor of bone (gct) is often regarded as a benigntumor, but its clinical course is unpredictable, has a high rate of recurrence, and even can metastasesand transform to a malignant tumor. histological features of the tumor often could not predict itsfuture biologic behavior, so it is just called ''giant cell tumor'' without indicating malignancy orbenignicity. several methods are suggested to predict the biologic behavior of this tumor. this studyevaluated the relation between bax & bcl-2 as proteins involved in cell proliferation and death(apoptosis) with histopathologic features and clinical course of gct.materials & methods: paraffin- embedded tissue specimens of 40 gcts of conventional,aggressive, recurrent, malignant, & metastatic types were evaluated by immunohistochemistry forbax & bcl-2 markers. clinicopathologic features and immunohistochemical results were statisticallyanalyzed and presented in tables & diagrams.results: age, sex, and pattern of skeletal involvement were the same as other worldwide reports.expression of bax & bcl-2 markers were significantly higher in malignant gcts but no statisticallysignificant difference was found in other subtypes for bcl-2 while there was statistically significantdifference between subgroups for bax.conclusion: considerable expression of bax & bcl-2 markers in a gct could signal its malignantcourse, but low expression is not valuable in predicting the clinical course. in addition, it seems thatsecondary tumor nodules in lung are just simple implantation not true malignant metastases