Rectal Sparing Approaches after Neoadjuvant Treatment for Rectal Cancer: A Systematic Review and Meta-Analysis Comparing Local Excision and Watch and Wait

SIMPLE SUMMARY: The increasing rate of complete response following neoadjuvant treatment for locally advanced rectal cancer has allowed an increasing interest for rectal-sparing approaches. Local excision and Watch and Wait allow the ability to avoid all the consequences and sequelae of Total Mesorectal Excision. However, despite excellent results in term of quality of life and bowel function, some concerns have been raised regarding the long-term outcomes. Most of the current studies compared Local Excision or Watch and Wait with Total Mesorectal excision, but only very few studies compare these two approaches. ABSTRACT: Local Excision (LE) or Watch and Wait (WW) for patients with complete clinical response or near-complete clinical response after neoadjuvant chemoradiotherapy (nCRT) were proposed to avoid morbidity and impairment of quality of life after rectal resection. The aim of this study is to perform a systematic review of the literature, and to compare rectal-sparing approaches, in terms of rectum-preservation rate, local control, and distant recurrences. A systematic review and meta-analysis were performed of studies published until July 2022 (PROSPERO, registration CRD42022341480), and the quality of evidence was assessed using a GRADE approach. Seven retrospective studies and one prospective trial were included. In six studies, patients were treated with standard long-course nCRT, and in two with Total Neoadjuvant Therapy (TNT). Overall, there were 213 and 188 patients in WW and LE group, respectively, and no difference was found between WW and LE when considering rectum-preservation rate (OR 0.80 95%CI 0.31–2.01, p = 0.63), local disease (OR 1.60 95%CI 0.75–3.42, p = 0.22), locoregional failure (OR 0.85 95%CI 0.20–3.66, p = 0.83) and distant recurrence (OR 0.76 95%CI 0.37–1.55, p = 0.45). Studies directly comparing WW and LE are still lacking, even though no differences between WW and LE in terms of rectum-preservation, local control, and distant recurrences have been found.