Effectiveness of Organ Preservation for Locally Advanced Rectal Cancer With Complete Clinical Response After Neoadjuvant Chemoradiotherapy: Bayesian Network Meta-analysis.

Background: Neoadjuvant chemoradiotherapy followed by radical surgery is the common treatment for patients with locally advanced rectal cancer. Presently, for patients with complete clinical response after neoadjuvant chemoradiotherapy, organ preservation ("watch-and-wait" and local excision strategies) has been increasingly favored. However, the optimal treatment for patients with complete clinical response remains unclear.

Objective: This study aimed to use Bayesian meta-analysis to determine the best treatment for patients with locally advanced rectal cancer with complete clinical response among radical surgery, local excision, and watch-and-wait strategies.

Data Sources: PubMed, Web of Science, Cochrane Library, and Embase (Ovid) databases were searched for literature published through December 31, 2023.

Study Selection: Studies that compared 2 or more treatments for patients with complete clinical response were included.

Intervention: The analysis was completed via Bayesian meta-analysis using a random-effects model.

Main Outcome Measures: Surgery-related complications, local recurrence, distant metastasis, and 5-year overall and disease-free survival rates.

Results: Eleven articles met the inclusion criteria. The watch-and-wait group and local excision group exhibited a higher rate of tumor recurrence compared to the radical surgery group (watch-and-wait vs radical surgery: OR, 9.10 [95% CI, 3.30-32.3]; local excision vs radical surgery: OR, 2.93 [95% CI, 1.05-9.95]). The distant metastasis, overall survival, and disease-free survival rates of the 3 treatments were not statistically different. The radical surgery group had the most number of stomas and had the greatest risk of morbidity than the watch-and-wait group (watch-and-wait vs radical surgery: OR, 0.00 [95% CI, 0.00-0.12]).

Limitations: The study included only 1 randomized controlled trial compared to 10 observational studies, which could affect overall quality. Funnel plots of disease-free survival rates and stoma suggest significant publication bias among studies that compared radical surgery with the watch-and-wait strategy.

Conclusions: The watch-and-wait strategy could be optimal for patients with locally advanced rectal cancer with complete clinical response after neoadjuvant chemoradiotherapy.