Chemotherapy After Colonic Stent in Patients With Unresectable Obstructive Colorectal Cancer: A Retrospective...

Backgrounds and study aim Placement of a self-expandable metallic stent (SEMS) has become a common practice for obstructive colorectal cancer. However, the safety and efficacy of systemic chemotherapy after SEMS placement remain unclear. Patients and methods This multicenter retrospective cohort study was conducted by the Japan Colonic Stent Safe Procedure Group across Japan to investigate the SEMS-related complications and clinical outcomes of chemotherapy in patients with unresectable obstructive colorectal cancer. Results A total of 289 patients were included in the study. The median duration from SEMS placement to chemotherapy initiation was 11 days (range, 6-21 days). SEMS-related complications occurred in 30.1% of the patients, with the most common complications being perforation (8.7%; 95% CI, 5.9-12.5A%), re-obstruction (19.4%), and migration (20.8%). Among the patients with stent migration, 30% required additional intervention. The median progression-free survival (PFS) was 9.2 months (95% confidence interval [CI], 7.5-10.9 months), and the median overall survival (OS) was 17.3 months (95% CI, 14.1-20.5 months). No significant difference in perforation rate was observed with or without bevacizumab use (14.5% vs. 7.3%, P < 0.107). Factors influencing survival outcomes included the number of metastatic organs, presence of perforation, and performance of primary tumor resection (PTR). Survival analyses showed that patients who underwent PTR had significantly better PFS and OS; however, this result should be interpreted with caution due to potential selection bias and immortal time bias inherent in the retrospective design. Conclusions This multicenter retrospective study demonstrated that while chemotherapy after SEMS placement is generally feasible, clinicians should remain vigilant for complications like perforation, migration, and re-obstruction.