CD44 expression in soft tissue sarcomas

Recent studies have shown that expression of alternatively splicing variants of CD44 is correlated with prognosis for several kinds of malignant tumors. However, little is known about the expression of CD44 standard and variant isoforms in soft tissue sarcomas. In this study 47 cases of soft tissue sarcoma [18 malignant fibrous histiocytomas (MFHs), 13 synovial sarcomas (SSs), 7 malignant schwannomas (MSs), and 9 liposarcomas (LSs)] were examined immunohistochemically. The monoclonal antibodies to the standard form of CD44 (CD44H) and variant exons of CD44v3, 4, 5, 6, 7, 9, and v10 were used. We analyzed the membranous expression pattern of CD44H and CD44 variant exons and assessed the relation between expression of CD44s and metastasis-free survival rates (MFSR) of patients with soft tissue sarcoma. A few sarcomas expressed CD44v3 (2/47) and v7 (2/47), but none of the sarcomas expressed CD44v10. CD44v4 (5/47), v5 (4/47), v6 (10/47), and v9 (9/47) are relatively common types of variant isoforms in soft tissue sarcomas. Expression of CD44v6 is more frequently detected in high-grade than in low-grade tumors. CD44v6 or CD44v9 expression was correlated with metastasis-free survival of patients with soft tissue sarcomas.