IMMUNOHISTOCHEMICAL AND CLINICAL-EVALUATION OF CATHEPSIN EXPRESSION IN SOFT-TISSUE SARCOMAS

Lysosomal proteases are known to enhance the spread of epithelial tumo ur cells, but little is known of the possible role of proteases in the growth of soft tissue sarcomas (ST). We investigated the expression o f cathepsins D, B, S, H, L and procathepsin L in frozen sections of 34 STS from 34 patients by immunohistochemistry (IHC). Cathepsins D, B a nd H were relatively highly expressed in STS (77-91%). The expression rate of cathepsins S and L and of procathepsin L was lower (40-66%). C athepsin S and L expression showed a moderate (P = 0.078 and P = 0.019 ) and procathepsin L a strong (P = 0.00001) correlation with the survi val rate of STS patients. Cathepsin S expression is also correlated wi th the local recurrence rate (P < 0.01). Lysosomal proteases may play a role in STS progression, and cathepsin expression may also have sign ificance as a prognostic factor in STS.