CD133 and nuclear beta-catenin: the marker combination to detect high risk cases of low stage colorectal cancer.

Nuclear beta-catenin and CD133 are linked with two hallmarks of colon cancer, wingless-type mouse mammary tumour virus integration site (WNT)-pathway dysregulation and colon cancer stem cells (Co-CSCs), respectively. Both molecules may be related, as Co-CSCs were proposed to require activated WNT-signalling and as CD133 was postulated as a WNT/beta-catenin target gene. Herein, we investigated the expression of these markers on serial sections of 162 stage IIA colonic adenocarcinomas. We found that the expression of these molecules is statistically independent and that they mark distinct but overlapping subpopulations of the tumour cells. Moreover, we show that their combined evaluation can identify colon cancer cases with vastly reduced survival (hazard ratio (HR) 13.4, 95% confidence interval (CI): 4.7-38.2) and a high risk of tumour progression (HR 6.8, 95%CI: 3.1-15.0). In conclusion, the independence of these markers may on the one hand have implications for their presumed value to identify Co-CSCs; on the other hand it allows their combined analysis to become a powerful tool to identify high risk cases of stage IIA colon cancer.