Dynamic monitoring of serum CEA and CA19-9 predicts the prognosis of postoperative stage II colon cancer

Background: We sought to investigate the prognostic significance of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) dynamics for stage II colon cancer patients undergoing radical resection.

Methods: This study retrospectively analyzed 1517 stage II colon cancer patients admitted to the Harbin Medical University Cancer Hospital from January 2011 to December 2016. To observe the relationship between tumor markers dynamic monitoring and survival, we calculated cut-off values for ΔCEA and ΔCA19-9. Group according to the cut-off values and compare the differences in survival between subgroups.

Results: Preoperative CA199 (HR = 3.122), postoperative CEA (HR = 2.941) and histological type (HR = 2.855) were independent prognostic factors in multivariate Cox proportional hazards models. The 5-year overall survival (OS) in the patients with normal preoperative CEA and CA19-9 was significantly better than the patients with elevated preoperative CEA or CA19-9 and the patients with elevated preoperative CEA and CA19-9 (92.6 % vs. 87.6 % vs. 81.0 %, P < 0.05). 469 patients with normal pre- and post-operative CEA had the highest 5-year OS (93.5 %, P < 0.05). Among the 177 patients with elevated pre- and post-operative CEA, the 5-year OS rate was only 81.8 % (P < 0.05). The cut-off values for Δ CEA and Δ CA19-9 in stage II colon cancer patients with elevated preoperative tumor markers were 2.625 ng/ml and 7.835 U/ml, respectively. The Kaplan-Meier curves showed that Δ CEA≥2.625 ng/ml and Δ CA19-9≥7.835 U/mL were associated with better outcome (87.8 % vs. 79.6 %, P < 0.05; 85.8 % vs. 79.1 %, P > 0.05). At the same time, we found that adjuvant chemotherapy significantly improved 5-year OS in patients with elevated preoperative CEA or CA19-9 (91.0 % vs. 80.9 % and 89.6 % vs. 80.2 %, P < 0.05).

Conclusions: Persistent postoperative elevation of CEA/CA19-9 is associated with a poor prognosis. CEA and CA19-9 may be high-risk factors for postoperative adjuvant therapy in stage II colon cancer patients. For stage II colon cancer patients with elevated preoperative CEA, patients with Δ CEA<2.625 ng/ml have poor survival and can improve prognosis by receiving adjuvant therapy.