Preoperative plasma soluble urokinase plasminogen activator receptor as a prognostic marker in rectal cancer patients. An EORTC-Receptor and Biomarker Group collaboration.

BACKGROUND AND AIMS

Since approximately 30% of patients with Dukes stage B colorectal cancer will experience disease recurrence within five years of primary treatment, current staging of patients with early colorectal cancer apparently fails to adequately predict patient outcome. It has previously been shown that the preoperative plasma concentration of soluble urokinase plasminogen activator receptor (suPAR) is associated with the survival of patients with early colo-rectal cancer. In this study we sought to confirm the independent prognostic value of suPAR in rectal cancer.

METHODS

suPAR was retrospectively determined by two different versions of a suPAR ELISA in preoperatively collected plasma samples from a Swedish (n=354) and a Danish (n=255) cohort of rectal cancer patients.

RESULTS

In both cohorts the suPAR concentration was significantly higher in Dukes stage D patients than in Dukes stage A-C patients (p<0.0001). Among Dukes stage A-C patients, no differences in median suPAR values were seen. In univariate analysis, continuous suPAR was found to be associated with survival (p<0.0001 in both cohorts). Of particular interest was that similar results were obtained for Dukes stage A and B patients when analyzed separately. In multivariate analysis, continuous suPAR was found in both cohorts to be independent of Dukes stage.

CONCLUSIONS

This study confirms that the preoperative concentration of plasma suPAR contains independent prognostic information on patients with rectal cancer. This result was independent of the two different versions of an in-house suPAR ELISA used to perform the analyses. The next step in the evaluation of suPAR as a prognostic parameter in rectal cancer will be to launch an appropriately dimensioned prospective study where the benefit of applying preoperative plasma suPAR measurement to clinical decision-making regarding adjuvant therapy is assessed. (Int J Biol Markers 2005; 20: 93-102).