Carcinoembryonic gene member 2 mRNA expression as a marker to detect circulating enterocytes in the blood of colorectal cancer patients

Abstract

Background. The aim of this study was to report our experience with a new molecular tool to detect circulating enterocytes in the blood of patients with colorectal cancer. Methods. The study included 193 individuals: 78 patients with colorectal cancer and 115 controls composed of patients with benign colorectal diseases (n = 16), patients with noncolorectal cancer (n = 31), healthy individuals (n = 62), and healthy bone marrow transplantation donors (n = 6). A nested reverse transcriptase-polymerase chain reaction with specific primers for the carcinoembryonic gene member 2 (CGM2) was used to detect circulating enterocytes in the peripheral blood of 78 patients with colorectal cancer. The blood (n = 109) or the bone marrow (n = 6) of the 115 controls was studied to test the absence of CGM2 illegitimate transcription in nucleated blood cells and nucleated blood cell progenitors. The assay sensitivity was effective in detecting 1 CGM2-positive cell per 106 nucleated blood cells. Results. Fifty-nine percent (46/78) of patients with colorectal cancer were found positive whereas all negative controls remained negative. Positivity rates were 38% (3/8) in Dukes' A classification, 43% (9/21) in Dukes' B, 77% (23/30) in Dukes' C, and 58% (11/19) in Dukes' D. Conclusions. The clinical significance of enterocyte detection in the blood of colorectal cancer patients by means of this CGM2 messenger RNA assay needs further evaluation. (Surgery 2001;129:587-94.)