Background: The Osaka system for soft-tissue sarcoma grading was proposed through an analysis of soft-tissue sarcoma (STS), treated from 1964 to 1989. The present study was conducted to evaluate the utility of the Osaka system under recent therapeutic regimens.
Patients and methods: One hundred and eleven patients with localized STSs arising in the trunk and extremities (66 males and 45 females; median age 57) were selected. Histological factors, argyrophilic nucleolar organizer region (AgNOR) count and Ki-67 labeling index (LI) were evaluated for prognostic significance.
Results: Univariate analysis revealed that histological classification, mitotic count, cellularity, AgNOR count, and Ki-67 LI were prognostically significant for survival. Multivariate analysis revealed Ki-67 LI as an independent prognostic factor. The five-year survival rate for low-, intermediate-, and high-grade STSs in Osaka grading was 94.6%, 75.2%, and 68.4%, respectively.
Conclusion: Osaka grading is a useful system for the decision-making of therapeutic modalities for STS.