Role of serum Metadherin mRNA expression in the diagnosis and prediction of survival in patients with colorectal cancer.

Early diagnosis and treatment of colorectal cancer (CRC) are important for improving patients' survival. Metadherin is an oncogene that plays a pivotal role in carcinogenesis and can be suggested as a cancer biomarker. This study aimed to elucidate the efficacy of serum Metadherin mRNA expression as a potential non-invasive biomarker for early diagnosis of CRC in relation to other screening markers as carcinoembryonic antigen (CEA), carbohydrate antigen 19.9 (CA19.9) and Fecal occult blood (FOB) and also to assess its relationship with the tumor stage and survival rate. A convenience series of 86 CRC cases (group I) were recruited with 78 subjects as controls (group II). Serum Metadherin mRNA expression level was determined using reverse transcription polymerase chain reaction (RT-PCR). Serum Metadherin mRNA expression level was significantly elevated in CRC cases when compared with controls (P < 0.001). For CRC diagnosis; Receiver operator characteristic (ROC) analyses revealed that the diagnostic accuracy of serum Metadherin mRNA (AUC = 0.976) was significantly higher than other routine CRC screening markers as CEA, CA19.9 and FOB. The combined accuracy of these markers (AUC = 0.741) was increased when used with serum Metadherin mRNA (AUC = 0.820). High serum Metadherin mRNA expression was associated with poorly differentiated histological grade, advanced tumor stage and lower survival rate. AUC of Metadherin was 0.820 for differentiating advanced versus early tumor stages. Serum Metadherin mRNA expression is a useful non-invasive biomarker for CRC. It can be used for screening and early diagnosis of CRC and can increase the efficacy of other routine CRC screening markers when it is estimated in CRC patients with them. It is also associated with advanced tumor stage and a lower survival rate.