Prognostic significance of CEA reduction rate in patients with abnormally high preoperative CEA levels who underwent surgery for lung cancer

Background The aim of this research was to investigates the prognostic importance of change in carcinoembryonic antigen (CEA) levels (particularly abnormal high concentration) in patients with non-small cell lung cancer (NSCLC) between before and after surgery. Methods The study involved 68 patients with NSCLC ( preoperative CEA value ≥ 10ng/ml) who received curative operation from 2012 to 2020. Preoperative and postoperative serum CEA levels, CEA reduction, and other clinicopathological factors were determined on medical records. Receiver operating characteristic curves were used to calculate cut-off levels for prognostic markers. Multivariate analyses with a Cox proportional hazards regression model were performed to identify Independent prognostic variables Results The optimal cut-off was value for the CEA reduction rate was 77.3%. The area under the curve for the CEA reduction rate was greater compared with those for preoperative and postoperative CEA levels. The Kaplan-Meier method revealed a significantly worse prognosis in the low CEA reduction rate group versus the high CEA reduction rate group regarding overall survival (OS) (p = 0.002). In the multivariate analysis, the CEA reduction rate (hazard ratio: 3.36, 95% confidence interval : 1.32-8.51, p = 0.011) was identified as an independent and exclusive prognostic marker for OS. Conclusions In NSCLC, which is characterized by high preoperative CEA levels, the CEA reduction rate after surgery is a useful prognostic factor. Importantly, it is a more powerful indicator for OS compared with postoperative CEA levels. This factor may be used to clarify the effectiveness of adjuvant therapy in such cases in the future.