CEACAM5 and rectal cancer: As compared to control group, the expression of circ-NOL10, circ-LDLRAD3, circ-RHOT1, and CEA level in CRC, colon cancer, and rectum cancer patients was significantly upregulated (P ˂ 0.001, 0.001, 0.002), while circ-SMARCA5 was insignificantly upregulated (P = 0.233, 0.264, 0.280 respectively).