CEACAM5 and neoplasm: Normal CEA level (SHR = 0.568, 95% CI: 0.385–0.837, P = 0.0043), tumor size >3.0 cm (SHR = 2.289, 95% CI: 1.388–3.776, P = 0.026), poor differentiation (SHR = 1.664, 95% CI: 1.013–2.733, P = 0.044), and primary tumor site in the rectum (SHR = 1.772, 95% CI: 1.204–2.607, P = 0.0037) were significant prognostic indicators for elderly T1 CRC patients.