Authors: Ştefan Toader, Laba Elisabeta


Introduction: Clinical and morphological heterogeneity, as well as variable therapeutic response of soft tissue sarcomas require introduction of immunohistochemical tests for a better identification of cellular subtypes and for better prognostic appreciation of these neoplasms. Aim of study was to determine accessible markers, useful for prognostic evaluation.
Material and method: 15 soft tissue sarcoma cases were included (different morphological types). For each case Ki67, p53 and Bcl-2 expression levels were analyzed. Tumoral angiogenesis was also evaluated using CD-34 marker. Results: Proliferative activity was analyzed using Ki67. 10 cases were Ki67 positive, with a level of expression > 20% (infantile fibrosarcoma, poorly differentiated fibrosarcomas, leiomyosarcomas: cutaneous, vascular and bizare, rhabdomiosarcomas: alveolar and pleomorphic, fibrous malignant hystiocytoma and angiosarcoma). 3 cases presented an expression level for Ki67 of 20% (embrionary rhabdomyosarcoma, synovial sarcomas: monophasic and biphasic). 2 cases presented an expression level for Ki67 < 20% (well differentiated fibrosarcoma and MPNST). Expression of the markers involved in apoptosis regulation (p53 and Bcl-2) was variable. 7 cases were negative both for p53 and for Bcl-2 (rhabdomyosarcomas, monophasic synovial sarcoma, infantile fibrosarcoma and leiomyo-sarcomas: cutaneous and bizare) in correlation with a Ki67 level Z 20% and an unfavourable clinical course. The case of well differentiated fibrosarcoma was p53 and Bcl-2 negative in correlation with a Ki67 level < 20%, showing a slow tumoral growth. 4 cases were p53 positive (5-30%) and Bcl-2 negative (poorly differentiated fibrosarcomas, fibrous malignant hystiocytoma, angiosarcoma). 3 cases were p53 negative and Bcl-2 positive (5-10%) (vascular leiomyosarcoma, biphasic synovial sarcoma and MPNST) proving an unlimited tumoral growth. Semiquantitative angiogenesis evaluation using CD-34 resulted in scores from 1+ to 4+. High angiogenesis scores (3+ and 4+) were associated with a high Ki67 level (> 20%) in poorly differentiated fibrosarcomas, alveolar rhabdomyosarcoma and angiosarcoma, emphasizing their aggressive clinical course. Conclusions: Ki67 expression level can be considered as an independent prognostic factor for soft tissue sarcomas. The ratio between the positive and negative expression of p53 and Bcl-2 in favour of the latest indicates an
unlimited tumoral growth. High angiogenesis scores (3+ and 4+) were associated with high Ki67 expression in some sarcomatous subtypes emphasizing their aggressive evolution and higher capacity of metastasis.