Treatment stratification and prognosis assessment using circulating tumor DNA in locally advanced rectal cancer: A systematic review and meta‐analysis

Abstract

BackgroundCirculating tumor DNA (ctDNA) is an emerging biomarker for locally advanced rectal cancer (LARC), giving hope for stratified treatment. As the completed studies have small sample sizes and different experimental methods, systematic review and meta‐analysis were performed to explore their role in predicting pathological complete response (pCR), tumor recurrence, and prognosis.MethodsPubMed, Embase, and the Web of Science were searched for potentially eligible studies published up to September 6, 2022. Pooled relative risk (RR) was calculated to predict pCR and tumor recurrence, and pooled hazard ratio (HR) was calculated to evaluate the prognosis of overall survival (OS), recurrence‐free survival (RFS), and metastasis‐free survival (MRS).ResultsTwelve studies published between 2018 and 2022 included 931 patients, and 2544 serum samples were eventually included in the meta‐analysis. The pooled revealed that ctDNA‐negative patients were more likely to have a pCR (RR = 1.64, 95% confidence interval [CI]: 1.26–2.12). The pooled revealed that ctDNA‐positive patients were at high risk of recurrence (RR = 3.37, 95% CI: 2.34–4.85) and had a poorer prognosis for OS (HR = 3.03, 95% CI: 1.86–4.95), RFS (HR = 7.08, 95% CI: 4.12–12.14), and MRS (HR = 2.77, 95% CI: 2.01–3.83).ConclusionctDNA may be useful for stratifying treatment and assessing prognosis in patients with LARC, but its clinical application still needs to be confirmed in a prospective multicenter study with large samples.

ctDNA as a predictor of outcome after curative resection for locally advanced rectal cancer: systematic review and meta‐analysis

“…[33] evaluated the role of ctDNA in predicting treatment response and prognosis, and reported similar findings [32,33]. However, the largest number of primary studies were incorporated in this review.…”

“…The strength of this study is that it is the largest systematic review and meta-analysis in the literature to assess the role of ctDNA in the management of LARC. It included a number of good quality cohort studies with consistent results regarding role of pre-and postoperative ctDNA when compared to other published reviews on this topic [31][32][33].…”