Prognostic significance of nuclear DNA content in chondrosarcoma

Chondrosarcoma is the second most frequent primary malignant tumor of bone. Many of these tumors represent histopathologic borderline cases. In this study, DNA ploidy status, 2c deviation index (2cDI), and DNA malignancy grade (DNA-MG; based on the variation of nuclear DNA content of tumor cells around the normal DNA [2c] peak) were examined for their diagnostic and prognostic value in comparison with conventional histopathologic grading. Twenty-two paraffin-embedded samples were available for histopathologic investigation and for quantitative cytophotometric DNA determination of Feulgen-stained nuclei. Clinicopathologic parameters and prognosis were analyzed over a maximum follow-up period of 252 months. Nineteen of 22 (86%) chondrosarcomas showed aneuploid DNA content. 2cDI (r =.58, P <.01) and DNA-MG (r =.58; P <.01) correlate with the histopathologic grading. Significant correlation between the 2cDI (P <.01) and DNA-MG (P <.025) and the overall survival was found. Ploidy did not influence the overall survival rate. In metastasis-free patients, the 2cDI and DNA-MG gave better prognostic information than conventional histopathologic grading. When patients developed metastasis, however, histopathologic grading was the prognostic parameter of choice. Cytometric DNA measurement provide additional objective information regarding the diagnosis and prognosis of chondrosarcomas, even more than that obtained by conventional histopathologic grading, and may be helpful in planning the treatment.