CEACAM5 and neoplasm: The clinical stage after crizotinib treatment was ycT2aN0M0, stage IB: 1) the serum CEA level decreased to 7.4 ng/ml once and increased slightly afterwards, 2) there is a possibility of tumor progression because of progression-free survival of crizotinib treatment, and 3) the patient’s hope for surgical resection of residual tumor was the reason for considering salvage surgery.