PROGNOSTIC IMPLICATIONS OF P53 NUCLEAR OVEREXPRESSION AND HIGH PROLIFERATION INDEX OF KI-67 IN ADULT SOFT-TISSUE SARCOMAS

Background: Morphologically similar soft-tissue sarcomas may behave in very different fashions, making it difficult to predict clinical outc omes and to properly design therapeutic interventions. In a preliminar y study, we observed that TP53 mutations and nuclear overexpression of p53 protein were frequent events in soft-tissue sarcoma, and we notic ed an association between p53-positive phenotype and poor clinical out come. Purpose: We examined the potential clinical relevance of p53 ove rexpression in adults with soft-tissue sarcomas. We also studied the c linical implications of a high proliferation index. Methods: A cohort of 174 adults with soft-tissue sarcomas were analyzed using anti-p53 a nd anti-Ki-67 antibodies and immunohistochemical assays on consecutive fresh frozen tissue samples. Results: We observed a significant assoc iation between p53 nuclear overexpression and tumor grade (P = .001) a nd tumor size (P = .01). Patients displaying a p53-positive phenotype had significantly reduced survival (P = .02). Similarly, a significant difference was observed between high proliferation index and tumor gr ade (P<.001) and reduced patient survival (P = .03). A high Ki-67 prol iferation index was detected in association with p53 nuclear overexpre ssion. Conclusions: Overexpression of p53 protein and a high prolifera tion index strongly: correlate with poor clinical outcome and reduced survival in patients having soft-tissue sarcomas.