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

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 still unclear. 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. PubMed, Web Of Science, Cochrane Library and Embase(Ovid) were searched until December 31, 2023. Studies that compared two or more treatments for patients with complete clinical response were included. The analysis was completed via Bayesian meta-analysis using random-effects model. Surgery-related complications, local recurrence, distant metastasis, 5-year overall and disease-free survival rate. Eleven articles met inclusion criteria. The groups of watch and wait and local excision exhibited a higher rate of tumor recurrence compared to radical surgery group (OR [95% CI]: watch and wait VS radical surgery: 9.10 [3.30, 32.3], local excision VS radical surgery: 2.93 [1.05, 9.95]). The distant metastasis, overall and disease-free survival rates of 3 treatments were not statistically different. The radical surgery group had the most number of stoma, and had the greatest risk of morbidity than the watch and wait group (OR[95%CI]: watch and wait VS radical surgery: 0.00 [0.00, 0.12]). 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 which compared radical surgery with watch and wait strategy. The watch and wait strategy could be optimal for patients with locally advanced rectal cancer with complete clinical response after neoadjuvant chemoradiotherapy.