Rectal cancer approach strategies after neoadjuvant treatment - a systematic review and network meta-analysis

An increasing number of patients with rectal cancer who respond well to neoadjuvant chemoradiotherapy (nCRT) are being considered for organ preservation programs. However, due to the lack of high-level evidence, the survival outcomes of the organ preservation programs are still full of controversy and uncertainty.

To assess the effects of total mesorectal excision (TME) surgery, watch-and-wait (W&W), and local excision (LE) on long-term outcomes after nCRT, we searched PubMed, Embase, and Web of Science for articles published between 1 January 2010, and 31 December 2023.

We found 7029 pieces of literature, of which 26 studies met the inclusion criteria, and recruited 2778 participants in the network meta-analysis. Risk of bias assessment showed that most included studies had a low risk of bias. Low-certainty evidence suggests that the TME group was significantly superior to all other interventions for the 2-year local regrowth rate. (W&W group [OR, 0.20; 95% CI, 0.12-0.35], LE group compared with TME group [3.00; 1.60-5.80]). There was no significant difference in the 2-year local regrowth rate between W&W and LE group (OR, 0.60; 95% CI, 0.32-1.20). There was high to moderate certainty evidence that at 3 years, the W&W group had a significant advantage in overall survival compared with the TME group (OR, 0.37; 95% CI, 0.09-0.95). After 5 years, no significant difference in overall survival was found between the 3 treatment modalities.

We concluded that TME achieved the most significant reduction in 2-year local regrowth rates. However, the W&W strategy and LE demonstrated noninferiority to TME in long-term survival outcomes.