Prognostic impact of carcinoembryonic antigen and carbohydrate antigen 19-9 in stage IV colorectal cancer patients after R0 resection

BackgroundAlthough preoperative carcinoembryonic antigen (pre-CEA) and carbohydrate antigen 19-9 (pre-CA 19-9) are reportedly prognostic indicators for colorectal cancer (CRC), the prognostic roles of postoperative CEA (post-CEA) and CA 19-9 (post-CA 19-9) shortly after surgery have not been clarified in patients with curatively resected stage IV CRC. The aim of this study was to evaluate the predictive abilities of post-CEA and post-CA 19-9.MethodsA total of 129 consecutive patients who had stage IV CRC and underwent R0 resection were retrospectively analyzed. Pre-CEA and post-CEA and CA 19-9 levels were measured within 1 mo before and 3 mo after surgery, respectively. Relapse-free survival (RFS) and overall survival were estimated using the Kaplan–Meier method, and multivariate analysis was performed using the Cox proportional hazards model.ResultsPre-CEA was elevated (≥5.0 ng/mL) in 73.6% of the patients and remained elevated after surgery in 32.7% of the patients. Elevated post-CA 19-9 (≥50 U/mL) was observed in 9.5% of the patients. Neither elevated pre-CEA nor elevated pre-CA 19-9 was significantly associated with RFS but both elevated post-CEA and elevated post-CA 19-9 were associated with markedly reduced RFS (P = 0.0002 and P = 0.0004, respectively). When considered in combination, post-CEA and post-CA 19-9 significantly stratified RFS and was an independent predictive factor for recurrence (P = 0.0035), as was lymphatic invasion (P = 0.0015). Post-CA 19-9 was the only evident independent predictive factor for overall survival (P = 0.0336).ConclusionsIn patients with stage IV CRC who underwent curative resection, the combination of post-CEA and post-CA 19-9 at 3 mo after surgery was a potent prognostic indicator for recurrence.