P-239 Effectiveness and safety of palliative surgical interventions for bowel obstruction in advanced staged colorectal cancer: A systematic review and network meta-analysis

Mechanical bowel obstruction is a critical condition that requires emergency life-saving interventions in patients with advanced colorectal carcinoma (CRC). While three current palliative approaches, namely emergency resection (ER), decompressive stoma (DS), and endoscopic stenting (ES), have been used, evidence from only head-to-head trials is available. Therefore, we conducted a network meta-analysis (NMA) to evaluate the effectiveness and safety of these treatments simultaneously. We searched PubMed, Medline, Embase, ClinicalTrial.gov, and Cochrane databases for studies that compared palliative surgical treatment strategies for CRC. Eligible studies must report at least one outcome of interest, such as clinical success, recurrent obstruction, and morbidity rate. We conducted a frequentist framework through a naïve NMA and a series of designed-adjusted analyses whereby data from randomized controlled trials (RCTs) were combined with data from non-randomized studies following down-weighting the size effect. We used P-scores (range 0 - 1) to rank the probability of the best treatment, with a higher score indicating a better treatment. Our NMA included three RCTs and 13 cohort studies involving 1422 patients (56,2% male, mean 67,7 years old) who underwent different palliative interventions. In most design-adjusted scenarios, DS had the highest probability of being the most successful (P-score: 0.76 – 0.88) and preventing recurrent obstruction (P-score: 0.91 – 0.95). Conversely, ES was the least successful for clinical success (P-score: 0.03 – 0.36) and avoiding recurrent obstruction (P-score: 0.02 – 0.26) in different scenarios. All approaches had similar results regarding morbidity in most scenarios. The cluster rank combined the probability of effectiveness and safety or less recurrent obstruction of all approaches in different scenarios, showing that DS is the best option overall, with cophenetic correlation coefficients of 0.94 and 0.92, respectively. Our NMA results suggest DS is the safest and most effective treatment for bowel obstruction in advanced staged colorectal cancers. This approach could be recommended for patients with malignant CRC obstruction. Future studies should confirm these results with large-scale RCTs.