Abstract
<title>Abstract</title> <p>To evaluate the stage-specific comparative effectiveness of diverting stoma as a bridge to surgery (DS-BTS) versus emergency resection (ER) in obstructive colorectal cancer. Summary Background Data: Bridge-to-surgery approaches relieve obstruction before elective resection, but most evidence concerns self-expanding metal stents and pools outcomes across stages. Diverting stoma is a relevant alternative where stenting is restricted, yet stage-specific DS-BTS versus ER comparisons remain limited. We performed a nationwide target trial emulation using the linked Taiwan National Health Insurance Research Database and Cancer Registry (2016–2022; follow-up through 2023). Patients with obstructive colorectal cancer undergoing primary tumor resection were classified as DS-BTS, ER, or same-admission diversion with resection (Both). The primary outcome was 90-day all-cause mortality. Inverse probability of treatment weighting was applied within each stage cohort, with propensity-score matching for sensitivity. Among 17,162 patients (DS-BTS, 1,135; ER, 14,594; Both, 1,433), associations were stage- and endpoint-dependent. In stage IV, DS-BTS was associated with lower 90-day mortality than ER (weighted OR, 0.54; 95% CI, 0.33–0.88) without long-term benefit. In stage III, DS-BTS was associated with worse long-term mortality (3-year weighted HR, 1.28; overall weighted HR, 1.32). In stage I–II, DS-BTS was associated with fewer postoperative complications without a mortality benefit. DS-BTS showed stage-dependent, endpoint-specific associations in obstructive colorectal cancer, with a short-term survival benefit in stage IV, fewer complications in stage I–II, but worse long-term mortality in stage III. These findings argue against uniform bridge-to-surgery use and support selective, stage-specific management.</p>