Saito Gota, Sadahiro Sotaro, Kamata Hiroko, Miyakita Hiroshi, Okada Kazutake, Tanaka Akira, Suzuki Toshiyuki
Department of Surgery, Tokai University, School of Medicine, Kanagawa, Japan.
Oncology. 2017;92(5):276-282. doi: 10.1159/000456075. Epub 2017 Feb 9.
Serum carcinoembryonic antigen (CEA) has been widely used for postoperative surveillance for colorectal cancer. However, serum CEA has a poor diagnostic accuracy for detecting recurrence. We tested the hypothesis that determining cutoff values according to the preoperative serum CEA levels would enhance the diagnostic accuracy.
Serum CEA was measured before and 1-6 months after surgery in 783 patients with curatively resected colon cancer from 2005 through 2013. The cutoff values during surveillance were determined separately according to preoperative serum CEA levels.
In patients with negative preoperative serum CEA, the diagnostic accuracy for recurrence was 89.1% when a postoperative cutoff value was set at 5 ng/mL. However, in patients with positive preoperative serum CEA, the diagnostic accuracy was 58.4% when a postoperative cutoff value was set at 5 ng/mL, and was 75.6% when a cutoff value was set at 8 ng/mL. Among patients with positive preoperative serum CEA, the recurrence-free survival rate was significantly lower in patients with a serum CEA of ≥8 ng/mL than those with a serum CEA of <8 ng/mL (p = 0.0018).
The diagnostic accuracy of serum CEA for recurrence is enhanced by separately setting cutoff values according to preoperative serum CEA.
血清癌胚抗原（CEA）已广泛用于结直肠癌术后监测。然而，血清CEA检测复发的诊断准确性较差。我们检验了根据术前血清CEA水平确定临界值可提高诊断准确性这一假设。
对2005年至2013年期间783例接受根治性结肠癌切除术的患者在手术前及术后1至6个月测定血清CEA。根据术前血清CEA水平分别确定监测期间的临界值。
术前血清CEA阴性的患者，术后临界值设定为5 ng/mL时，复发诊断准确性为89.1%。然而，术前血清CEA阳性的患者，术后临界值设定为5 ng/mL时，诊断准确性为58.4%，临界值设定为8 ng/mL时，诊断准确性为75.6%。术前血清CEA阳性的患者中，血清CEA≥8 ng/mL的患者无复发生存率显著低于血清CEA<8 ng/mL的患者（p = 0.0018）。
根据术前血清CEA分别设定临界值可提高血清CEA检测复发的诊断准确性。
