Detection of fecal interferon-induced transmembrane protein messenger RNA for colorectal cancer screening.

Interferon-induced transmembrane protein (IFITM) is reported to be frequently overexpressed in colorectal tumors. This study aimed to determine the usefulness of detecting fecal IFITM messenger RNA (mRNA) by real-time reverse-transcription polymerase chain reaction (RT-PCR) for colorectal cancer (CRC) screening. This pilot study included 21 patients with CRC and 23 healthy controls. Total RNA was isolated from the feces of the patients, and the expression levels of the mRNA of IFITM1, IFITM2 and IFITM3 were measured by real-time RT-PCR to detect CRC. Receiver operating characteristic curves of respective genes were generated, and the area under the curve (AUC), sensitivity and specificity were determined. When the 44 patients were analyzed, the AUCs of fecal IFITM1, IFITM2 and IFITM3 expression analysis were 0.82, 0.80 and 0.65, respectively. The sensitivities were 67% [14/21; 95% confidence interval (CI) 43-85%], 67% (14/21; 95% CI 43-85%) and 71% (15/21; 95% CI 48-89%), respectively; and the specificities were 96% (1/23; 95% CI 78-100%), 96% (1/23; 95% CI 78-100%) and 61% (9/23; 95% CI 39-80%), respectively. When IFITM1 and IFITM2 were combined, the sensitivity was 86% (18/21; 95% CI 64-97%) and the specificity was 96% (1/23; 95% CI 78-100%). The fecal expression analysis of IFITM1 and IFITM2 mRNA by real-time RT-PCR for CRC screening exhibited high specificities, and the sensitivity was further improved by combining IFITM1 and IFITM2.