CEACAM5 and non-small cell lung carcinoma: However, when the cut-off value of CEA is adjusted according to the instructions (cut-off value: 5.0 ng/mL, sensitivity: 0.500, specificity: 0.980, accuracy: 0.650), the diagnosis of NSCLC with CEA (accuracy: 0.650) is much lower than that with RRM2 (accuracy: 0.738).