CEACAM5 and lung adenocarcinoma: The levels of CEA predict the 5-year survival rate of patients: 69% of patients have a CEA level below 5 ng/mL, 44% have a level of 5–200 ng/mL, and only 7% have a level equal or greater than 200 ng/mL.162 The elevated CEA level also has a bearing on poor prognosis and progression of lung adenocarcinoma patients with mutant EGFRs, and gastric cancer patients with lymph node metastasis.163 Additionally, CEA is also used for efficacy evaluation and recurrence detection after tumor treatment.164