【Objective】 The aim of this study was to investigate the relationship between 18F-FDG PET/CT findings and the serum tumor marker CEA in lung adenocarcinoma and regional lymph nodes

to improve the diagnostic accuracy of lung cancer. 【Methods】 In total 71 histologically diagnosed lung adenocarcinoma patients without any radiotherapy underwent 18F-FDG PET/CT were entered into this retrospective study. The concurrent serum antigen determination of peripheral blood carcino-embryonic antigen (CEA) by immune analysis were recorded in all patients. To analyze the relationship between the maximum standardized uptake value (SUVmax) in primary tumor

differentiation degree

tumor size

regional lymph node N staging

lymph node metastasis SUVmax and serum tumor marker CEA of selected patients. 【Results】 There was positive correlation between the primary tumor SUVmax

tumor size

and the serum CEA (P < 0.05). The regional lymph node N staging and serum CEA were also correlated

the difference of N0 ~ N3 stages had a statistical significance (P < 0.05)

but there was no correlation between differentiation degree of primary tumor

metastatic lymph node SUVmax and the serum CEA concentration. 【Conclusion】 There was positive correlation between primary tumor SUVmax

tumor size

lymph node N staging situation

and the serum CEA in lung adenocarcinoma. With the increased N staging

the serum CEA concentration is increasing gradually.