Association between RCASI expression and clinical outcome in uterine endometrial cancer

RCASI, which acts as a ligand for a putative receptor on immune cells such as peripheral lymphocytes and natural killer cells, is strongly expressed in human cancers. RCASI can induce these cells to undergo apoptotic cell death, which suggests that RCASI expression may prohibit the stromal reaction occurring in a tumour. To clarify the clinical significance of RCASI expression in uterine endometrial cancer, we analysed the association between RCASI expression and clinicopathologic variables by statistical methods. With the use of immunohistochemical techniques, we performed a retrospective study of RCASI expression in resected tumour tissue from 147 patients with uterine endometrial cancer. We evaluated the statistical correlation between RCASI expression and clinicopathologic variables, RCASI was expressed in 106 of 147 patients with uterine endometrial cancer; 30 of these 147 patients showed RCASI overexpression. Overexpression of RCASI was significantly correlated with age at surgery, stage, extent of myometrial invasion, and positive peritoneal cytologic results. Multivariate analysis revealed that RCASI expression and metastasis were clinically significant prognostic factors for the overall survival. These findings indicated that analysis for RCASI expression can provide crucial information about the clinical behaviour of uterine endometrial cancer, which may be valuable for the management of patients with this disease.