The Correlation Between Survival Benefit of Preoperative Radiotherapy and Pretreatment Carcinoembryonic Antigen Level in Locally Advanced Rectal Cancer.

Lei Wang,Lingdong Shao,Gang Chen,Huaqin Lin,Xiaohong Zhong,Junxin Wu

doi:10.3389/fonc.2021.735882

Abstract

BackgroundPreoperative radiotherapy followed by radical surgery is the standard treatment for locally advanced rectal cancer; however, its long-term survival benefit remains controversial. This study aimed to determine the relationship between pretreatment carcinoembryonic antigen (CEA) levels and the long-term prognosis of preoperative radiotherapy in locally advanced rectal cancer (LARC) patients.MethodsData of LARC patients who underwent surgery between 2011 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database, and patients were accordingly divided into surgery (S) group and radiotherapy followed by surgery (RT+S) group. The primary outcomes were cancer-specific survival (CSS) and cancer-specific mortality (CSM). CSS was evaluated using Kaplan-Meier analysis, while CSM was evaluated using a competitive risk model. Subgroup analysis was also conducted, which was stratified by pretreatment CEA levels.ResultsA total of 2,760 patients were eligible for this study, including 350 (12.7%) patients in the S group and 2,410 (87.3%) in the RT+S group. There were no significant differences in the CSS and CSM rates at 1, 3, and 4 years between the S and RT+S groups before and after PSM (all p > 0.05). Pretreatment CEA levels were independently associated with CSS and CSM after adjusting for age, sex, stage, pathological factors, and treatment factors (all p < 0.05). Subgroup analysis showed that preoperative radiotherapy would benefit patients with elevated CEA in terms of CSS and CSM (both p < 0.05) but not those patients with normal CEA (both p > 0.05). Further analysis showed that preoperative radiotherapy was an independent protective factor for CSS and CSM in patients with elevated CEA levels (both p < 0.05).ConclusionsPretreatment CEA level may be considered a potential biomarker to screen LACR patients who would benefit from preoperative radiotherapy in terms of long-term prognosis.

Highlights

Preoperative radiotherapy, either long-course radiotherapy (LCRT) or short-course radiotherapy (SCRT), is the standard neoadjuvant strategy for locally advanced rectal cancer (LARC) [1, 2]
Pretreatment Carcinoembryonic antigen (CEA) levels were independently associated with cancer-specific survival (CSS) and cancer-specific mortality (CSM) after adjusting for age, sex, stage, pathological factors, and treatment factors
Pretreatment CEA level may be considered a potential biomarker to screen LACR patients who would benefit from preoperative radiotherapy in terms of long-term prognosis

Summary

Introduction

Preoperative radiotherapy, either long-course radiotherapy (LCRT) or short-course radiotherapy (SCRT), is the standard neoadjuvant strategy for locally advanced rectal cancer (LARC) [1, 2]. As a hard endpoint of treatment, the long-term survival benefit of preoperative radiotherapy remains controversial, regardless of LCRT and SCRT [7,8,9,10,11]. We selected LARC patients diagnosed between 2011 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database to identify the long-term survival benefit of preoperative radiotherapy and to determine the relationship between the pretreatment CEA level and the prognosis of patients receiving preoperative radiotherapy. Preoperative radiotherapy followed by radical surgery is the standard treatment for locally advanced rectal cancer; its long-term survival benefit remains controversial. This study aimed to determine the relationship between pretreatment carcinoembryonic antigen (CEA) levels and the long-term prognosis of preoperative radiotherapy in locally advanced rectal cancer (LARC) patients

Objectives

Methods

Results

Conclusion