Prognostic Effect of Pretreatment Serum Carcinoembryonic Antigen Level

Many studies have reported the prognostic value of pretreatment serum carcinoembryonic antigen (pre-CEA) levels on colorectal cancer outcomes. However, controversy remains concerning the significance of pre-CEA levels in patients with rectal cancer treated with neoadjuvant chemoradiotherapy (CRT). Our aim in this study was to investigate the prognostic role of the pre-CEA level in patients with locally advanced rectal cancer undergoing neoadjuvant CRT followed by total mesorectal excision (TME). A total of 419 patients with stages II and III rectal cancer treated with neoadjuvant CRT followed by TME with available pre-CEA data were included. The outcomes studied were 5-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and diseasefree survival (DFS). Optimal pre-CEA cutoff values to predict DMFS were determined based on current smoking history. The median pre-CEA level of smokers was 3.8 ng/mL, and that of nonsmokers was 2.8 ng/mL (P< 0.01). Pre-CEA levels of 6.6 ng/mL for nonsmokers and 11.4 ng/mL for smokers were determined to best separate patients on the basis of time to distant metastasis by using log-rank statistics. The pre-CEA level was associated with DMFS (hazard ratio1⁄4 1.743, 95% confidence interval1⁄4 1.129–2.690, P1⁄4 0.01). The pre-CEA level was not associated with LRFS or DFS.The pre-CEA level appears to be a significant preoperative prognostic factor. Moreover, it is as valuable as any known pathologic factor. Future studies evaluating oncologic outcomes should take into consideration the pre-CEA level. (Medicine 94(31):e1291) Abbreviations: CEA = carcinoembryonic antigen, CRM = circumferential resection margin, CRT = chemoradiotherapy, CT ok Kim, MD, PhD, and Young Jin Kim, MD, PhD complete response, TME = total mesorectal excision, TRG = tumor