Serum angiogenin as a potential biomarker for early detection of colorectal adenomas and colorectal cancer

Although colorectal cancer (CRC) is one of the most common causes of cancer mortality, early-stage detection dramatically improves survival rate. To explore the feasibility of serum angiogenin (ANG) as a biomarker for early detection of colorectal neoplasia, we collected serum samples from 781 participants, including 369 patients with CRC, 133 with colorectal adenoma and 279 healthy controls. We examined the levels of serum ANG by ELISA, calculated the diagnostic accuracy of ANG by plotted receiver operating characteristic curves (ROCs), and compared it with those obtained by carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9). We also analyzed the relationship between serum ANG level and TNM stage in CRC patients. The results showed that ANG serum levels were significantly elevated in patients with colorectal adenomas and CRC (P < 0.01). The area under the ROC curve (AUC) for ANG in distinguishing CRC patients from healthy controls was 0.740 [95% confidence interval (CI): 0.705-0.744], comparable to that of CEA (0.770; 95% CI: 0.735-0.802; P = 0.26) but significantly higher than that of CA19-9 (0.636; 95% CI: 0.598-0.674, P < 0.01), with much higher sensitivity (67.75%) than CEA (36.86%) or CA19-9 (12.20%). We observed no significant differences in ANG serum levels among CRCs at different TNM stages. Furthermore, sensitivity and specificity of ANG for distinguishing colorectal adenomas patients from healthy controls were 66.20% and 64.90%, respectively. ANG has the potential to serve as a serum biomarker for early detection of colorectal neoplasia.