Multimarker Phenotypes of Colorectal Cancer

Gurzu Simona1, Jung I¹, Szakács Orsolya², Csernák Erzsébet², Tóth Erika², Popa D³, Szentirmay Z²

1 Department of Pathology, University of Medicine and Pharmacy of Tîrgu Mureş, Romania
2 Department of Pathology and Molecular Biology, National Institute of Oncology, Budapest, Hungary
3 Department of Anatomy and Embryology, University of Medicine and Pharmacy of Tîrgu Mureş, Romania

Objective: We tried to correlate the clinico-pathologically features of colorectal cancer (CRC) to expression of eight immunohistochemically (IHC) markers and microsatellite instability (MSI) in order to realyze a molecular subdivision of these tumors.
Methods: 300 CRC, surgical specimens, were statistically and IHC evaluated. MSI status was analyzed in 52 cases, with Real Time PCR, melting point analysis. The following IHC markers have been used: CD8, E-cadherin, HER-2, p53, Ki67, bcl-2, MLH-1, CEA. The molecular phenotypes have been reported to the node status (pN) and MSI.
Results: Based on statistically analyses, we revealed that CEA and Ki67 were not prognostic factors. MLH-1 may indicate the MSI status and the number of tumor inflitrated lymphocytes stained with CD8 seems to be higher in the MSI cases and tumors of the proximal colon. HER-2 expression was correlated to number of the lymph node metastatses and bcl-2 was negative is most of the CRC diagnosed in advanced stages.
Conclusions: The CRC may be subdivided in six molecular prognostic groups, the best prognosis showing the MSI/p53-/bcl-2+/HER-2- and the worst MSS/p53+/bcl-2±/HER-2+. These molecular subdivision may be the basis for targeted therapy in node negative CRC.