International Journal of Surgical Pathology 5(1 & 2):1-10, 1997 p53 Accumulation in Malignant Bone Tumors: An Immunohistochemical Analysis of 217 Cases

Using formalin-fixed paraffin-embedded tissue specimens, the authors studied the accumulation of p53 protein in various malignant bone tumors. p53 accumulation was detected in osteosarcoma (16.7%), malignant fibrous histiocytoma (MFH) of bone (30.4%), and chordoma (16.7%). In osteosarcoma, no difference was seen in the incidence of p53 accumulation according to the histologic grade of malignancy and any clinical factors including prognosis, but the incidence was significantly higher in conventional osteosarcoma than in other subtypes of osteosarcoma. In MFH of bone, the p53-positive group had a significantly worse prognosis compared with the p53-negative group. p53 accumulation is thus considered to be related to the prognosis of MFH of bone although it did not demonstrate any prognostic value for osteosarcoma in the current study. Int J Surg Pathol 5(1/2):1-10, 1997 Key words: p53 accumulation, immunohistochemistry, prognosis, osteosarcoma, malignant fibrous histiocytoma of bone, malignant bone tumor. p53 is a well-known tumor suppressor gene, lo-cated on chromosome 17p, and encodes a 53kD nu-clear phosphoprotein. The wild-type p53 gene product can reduce the transforming efficiency of many oncogenes and can suppress tumor growth [1], while the mutated p53 acts as a dominant onco-gene. Alterations of the p53 gene are observed in a broad spectrum of human neoplasms, thus suggest-ing that p53 gene mutations take part in the neo-plastic transformation of many types of human neoplasms [2,3]. The relationship between abnor-malities of the p53 gene and human neoplasms has From the *Second Department of Pathology; the tDepartmen