Ki-67 is strongly prognostic in synovial sarcoma: analysis based on 86 patients from the Scandinavian Sarcoma Group Register

In a study based on formalin-fixed paraffin-embedded material from 86 patie nts with primary synovial sarcoma located in the extremities or on the trun k wall, the prognostic importance of MIB-1 index, p53-expession and tumour size was analysed. Multivariate analysis identified two metastatic risk fac tors: increasing tumour size and MIB-1 >9%. The 5-year metastasis-free surv ival-rate for patients with tumour size greater than or equal to 5 cm + MIB -1 <10% was 0.83 (95% confidence interval (CI) 0.64-0.92) compared to 0.31 (95% CI 0.11-0.53) in cases with tumour size >5 cm + MIB-1 greater than or equal to 10%. Our study shows that metastatic disease in synovial sarcoma i s closely related to MIB-1 index. Using our model based on tumour size and MIB-1 index, cases with good and poor prognosis can easily be discriminated . Therefore our model can be used to identify patients who should be consid ered for adjuvant chemotherapy.