Published online Oct 15, 2022. doi: 10.4251/wjgo.v14.i10.2014
Peer-review started: June 8, 2022
First decision: June 23, 2022
Revised: July 6, 2022
Accepted: August 22, 2022
Article in press: August 22, 2022
Published online: October 15, 2022
Processing time: 128 Days and 6.9 Hours
Multiple classes of molecular biomarkers have been studied as potential predictors for rectal cancer (RC) response. Carcinoembryonic antigen (CEA) is the most widely used blood-based marker of RC and has proven to be an effective predictive marker. Cancer antigen 19-9 (CA19-9) is another tumor biomarker used for RC diagnosis and postoperative monitoring, as well as monitoring of the therapeutic effect. Using a panel of tumor markers for RC outcome prediction is a practical approach.
To assess the predictive effect of pre-neoadjuvant chemoradiotherapy (NCRT) CEA and CA19-9 levels on the prognosis of stage II/III RC patients.
CEA and CA19-9 levels were evaluated 1 wk before NCRT. According to the receiver operating characteristic curve analysis, the optimal cut-off point of CEA and CA19-9 levels for the prognosis were 3.55 and 19.01, respectively. The novel serum tumor biomarker (NSTB) scores were as follows: score 0: Pre-NCRT CEA < 3.55 and CA19-9 < 19.01; score 2: Pre-NCRT CEA > 3.55 and CA19-9 > 19.01; score 1: Other situations. Pathological information was recorded according to histopathological reports after the operation.
In the univariate analysis, pre-NCRT CEA < 3.55 [P = 0.025 for overall survival (OS), P = 0.019 for disease-free survival (DFS)], pre-NCRT CA19-9 < 19.01 (P = 0.014 for OS, P = 0.009 for DFS), a lower NSTB score (0-1 vs 2, P = 0.009 for OS, P = 0.005 for DFS) could predict a better prognosis. However, in the multivariate analysis, only a lower NSTB score (0-1 vs 2; for OS, HR = 0.485, 95%CI: 0.251-0.940, P = 0.032; for DFS, HR = 0.453, 95%CI: 0.234-0.877, P = 0.019) and higher pathological grade, node and metastasis stage (0-I vs II-III; for OS, HR = 0.363, 95%CI: 0.158-0.837, P = 0.017; for DFS, HR = 0.342, 95%CI: 0.149-0.786, P = 0.012) were independent predictive factors.
The combination of post-NCRT CEA and CA19-9 was a predictive factor for clinical stage II/III RC patients receiving NCRT, and the combined index had a stronger predictive effect.
Core Tip: Tumor microenvironment (TME) combined with neoadjuvant chemotherapy (NCRT) is the standard treatment for resectable stage II/III rectal cancer (RC). Multiple classes of molecular biomarkers have been studied as potential predictors for RC response but there is no sufficient evidence for any of them to be introduced into clinical practice. By retrospectively evaluating clinical stage II/III RC patients undergoing NCRT followed by standard TME, we found that the combination of NCRT carcinoembryonic antigen and carbohydrate antigen 19-9 levels could be a prognostic predictor for clinical stage II/III RC patients receiving NCRT, and the combined indexes had a stronger predictive effect than the index alone.