Prognostic significance of CD100 expression in soft tissue sarcoma

BACKGROUND. CD100, a class IV semaphorin, promotes angiogenesis, invasive growth, proliferation, and antiapoptosis of cancer cells in vitro. The expression of CD100 in soft tissue sarcoma (STS) and its correlation with clinicopathologic factors and prognostic significance were evaluated. METHODS. Expression levels of CD100 in patients with localized STS were evaluated immunohistochemically on paraffin- embedded sections from 81 patients, including 47 men and 34 women with a median age of 54 years. Staining intensity was categorized into weaker than (level 1) or equal to that of lymphocytes with a rate of < 10% stained tumor cells (level 2) or > 10% stained tumor cells (level 3). Ki-67 staining was performed in parallel. RESULTS. Forty-two tumors (52%) had level 1 CD100 expression, 18 tumors (22%) had level 2 CDIOO expression, and 21 tumors (26%) had level 3 CD100 expression. Tumors that had level 2 and 3 CD100 expression were correlated significantly with higher mitotic count, cellularity, ratio of necrosis, and Ki-67 labeling index (LI) compared with tumors that had level 1 CD100 expression. There was no correlation between CD100 expression and other characteristics. Among the 3 levels of CD100 expression, higher expression levels were correlated with poorer overall and disease-free survival. Multivariate analysis revealed that CD100 expression (levels 1 and 2 vs level 3) and tumor size (<= 5 cm vs > 5 cm) were independent prognosticators for overall survival (P <.05 for both), and CD100 expression (levels 1 and 2 vs level 3) was an independent prognosticator for disease-free survival (P <.05). CONCLUSIONS. The results from this study indicated the demonstrated prognostic significance of CD100 expression in STS.