Prognostic significance of microrna-21 expression in patients with unresectable metastatic colon cancer

Abstract

Background/Aim: MicroRNA (miR)-21 is overexpressed in most solid tumors and a high expression of miR-21 in tumor tissue is associated with a poor clinical outcome. The aim of this study was to clarify the association between the miR-21 expression in the tumor and the chemotherapeutic outcomes and survival for unresectable metastatic colon cancer (CC). Materials and Methods: Formalin-fixed, paraffin-embedded (FFPE) samples of primary tumor were obtained from 32 patients who underwent primary tumor resection and received palliative chemotherapy for unresectable metastatic CC. MiR-21 was extracted from the FFPE and the expression of miR-21 was evaluated using quantitative real time-polymerase chain reaction (RT-PCR). The expression of miR-21 was calculated with 2-CT. Results: A high miR-21 expression was associated with reduced progression-free survival (PFS) (p=0.0109) and tended to reduce overall survival (OS) (p=0.0675). Conclusion: miR-21 expression might be a useful prognostic marker for chemotherapeutic outcome and survival in patients with unresectable metastatic CC.