Carcinoembryonic Antigen Improves the Performance of MagneticResonance Imaging in the Prediction of Pathologic Response afterNeoadjuvant Chemoradiation for Patients with Rectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

ABSTRACT

Purpose@#The purpose of this study was to investigate the role of carcinoembryonic antigen (CEA) levelsin improving the performance of magnetic resonance imaging (MRI) for the predictionof pathologic response after the neoadjuvant chemoradiation (NCRT) for patients with rectalcancer. @*Materials and Methods@#We retrospectively reviewed the medical records of 524 rectal cancer patients who underwentNCRT and total mesorectal excision between January 2009 and December 2014. Theperformances of MRI with or without CEA parameters (initial CEA and CEA dynamics) forprediction of pathologic tumor response grade (pTRG) were compared by receiver-operatingcharacteristic analysis with DeLong’s method. Cox regression was used to identify the independentfactors associated to pTRG and disease-free survival (DFS) after NCRT. @*Results@#The median follow-up was 64.0 months (range, 3.0 to 113.0 months). On multivariate analysis,poor tumor regression grade on MRI (mrTRG; p < 0.001), initial CEA (p < 0.001) andthe mesorectal fascia involvement on MRI before NCRT (mrMFI; p=0.054) showed associationwith poor pTRG. The mrTRG plus CEA parameters showed significantly improved performancesin the prediction of pTRG than mrTRG alone. All of mrTRG, mrMFI, and initial CEAwere also identified as independent factors associated with DFS. The initial CEA further discriminatedDFS in the subgroups with good mrTRG or that without mrMFI. @*Conclusion@#The CEA parameters significantly improved the performance of MRI in the prediction ofpTRG after NCRT for patients with rectal cancer. The DFS was further discriminated by initialCEA level in the groups with favorable MRI parameters.