Abstract
The loss of adhesion molecules is reported to be associated with tumor invasion and metastasis in numerous types of cancer. Epithelial (E)-cadherin is an important molecule for cell-to-cell adhesion, while cluster of differentiation (CD)44 is an important molecule for cell-to-extracellular matrix adhesion. The focus of the present study was to evaluate the significance of the expression of E-cadherin and CD44 in patients with the unresectable metastatic colorectal cancer (CRC) who are undergoing palliative chemotherapy. Formalin-fixed, paraffin-embedded samples were obtained from 49 patients who underwent primary tumor resection and who were receiving palliative chemotherapy for unresectable metastatic CRC. The expression of E-cadherin and CD44 was evaluated using immunohistochemistry. The expression of E-cadherin was not significantly associated with progression-free survival (PFS; P=0.2825) or overall survival (OS; P=0.6617). The expression of CD44 was not associated with PFS (P=0.4365), but it did exhibit a certain level of association with OS (P=0.0699). However, the combined low expression of E-cadherin and CD44 demonstrated a significant association with decreased PFS (P=0.0101) and OS (P=0.0009). The combined loss of E-cadherin and CD44 expression also led to a reduction in the objective response rate and disease control rate (P=0.0076 and P=0.0294, respectively). A univariate analysis indicated that the combined low expression of E-cadherin and CD44 (P=0.0474) and sex (P=0.0330) were significantly associated with decreased PFS, and multivariate analysis confirmed combined low expression of E-cadherin and CD44 as an independent risk factor for decreased PFS [hazard ratio (HR), 8.276; 95% confidence interval (CI), 1.383-43.311; P=0.0227]. Univariate and multivariate analyses also indicated that the combined low expression of E-cadherin and CD44 expression was a significant prognostic factor for poor OS (HR, 15.118; 95% CI, 2.645-77.490; P=0.0039). Therefore the current study suggests that the combined low expression of E-cadherin and CD44 is an effective independent predictor of decreased chemotherapeutic outcome and survival in patients with unresectable metastatic CRC.