Prediction of lymph node metastasis in colorectal carcinoma by expressionof chemokine receptor CCR7.

Chemokine receptors are known to regulate homing of lymphocytes into secondary lymphoid organs and may also be involved in the lymphatic spread of solid tumors. Therefore, the assessment of chemokine receptor expression on colorectal carcinomas could potentially improve the prediction of lymph node spread. This is of great importance for the selection of patients for local therapy without the need for concomitant lymphatic dissection. Currently, only 5% of all patients can be selected for this desirable treatment option by established prognosticators. In a retrospective study, expression levels of the chemokine receptors CCR7, CXCR4 and CXCR5 were determined by immunohistochemistry on paraffin-embedded specimens of 99 colorectal carcinomas, which were curatively operated on, comprising all stages of the disease. Receptor expressions (absent vs. positive) from the overall tumor (OT) and from the invasion front (IF) including further prognosticators were correlated with lymph node status by uni- and multivariate analysis. Data were also correlated with synchronous distant metastases and overall survival. Median follow-up was 64 months. In univariate analysis, lymph node status correlated significantly with lymphovascular invasion, the expression of CCR7 IF, CCR7 OT, CXCR4 IF and CXCR4 OT, as well as pT category. Multivariate analysis revealed a significant correlation of lymph node status with lymphovascular invasion and CCR7 IF expression level. Most interestingly, CCR7 IF expression was significantly linked to decreased survival. CCR7 plays an important role in the mechanism of lymph node spread in colorectal carcinoma. Evaluation of the chemokine receptor expression profile seems to be appropriate to improve the selection of patients suited for local treatment and might constitute targets for nonsurgical therapy. (c) 2005 Wiley-Liss, Inc.