An Evidence-Based Review of Watch-and-Wait Strategy in Locally Advanced Rectal Cancer Achieving Complete Response After Neoadjuvant Chemoradiotherapy

To compare the clinical outcomes of the W&W strategy and surgery in locally advanced rectal cancer patients who achieved a clinical complete response (cCR) status post-neoadjuvant therapy. We searched for meta-analyses, clinical trials, and observational studies comparing two treatment strategies up to May 2023 in several databases, including PubMed, Embase, and Cochrane Library. We reported the article selection process according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and appraised the studies using the Oxford Center for Evidence-Based Medicine criteria. From 164 articles, we included two meta-analyses, one clinical trial, and four observational studies that met the criteria of validity, importance, and applicability. These studies indicated that the proportion of patients adopting the W&W strategy was limited. Most studies showed that the W&W group had a higher local recurrence rate than the surgery group. However, there was no significant difference in metastasis rates, disease-free survival (DFS), and overall survival (OS). The W&W strategy could be decided upon by a multidisciplinary approach in rectal cancer patients achieving cCR status after neoadjuvant therapy. Despite the higher local recurrence rate in the W&W group, strict surveillance and salvage therapy could provide a similar outcome.