ACBC Study Protocol – Acute Colon Resection Versus Bridge to Colon Surgery with Stent Placement or Stoma Diversion: A Prospective Cohort Study

Abstract

Abstract Background: Approximately 70% of all colon cancer emergencies result from colonic obstruction. Data from the Swedish Colorectal Cancer Registry indicate that patients undergoing emergency surgical resections for colon cancer face higher overall 30-day morbidity and increased mortality rates—5.8% at 30 days and 11.2% at 90 days—compared to those undergoing elective procedures, which have mortality rates of 1.1% and 2.0%, respectively. Other concerns about acute colon cancer resections are oncological outcomes. Long-term outcomes are significantly worse, with higher rates of recurrence and cancer-related death, regardless of the cancer stage or the use of adjuvant chemotherapy. Objectives: To evaluate the short- and long-term outcomes of primary resection for malignant colonic obstruction compared to only decompression using a self-expandable endoscopic metallic stent or diverting stomas as the first intervention (bridge to surgery) followed by later oncological resection. Design: This is a prospective observational study with data collected through the Swedish Colorectal Cancer Registry with an additional electronic case report form. Settings: Swedish multicenter study at both university and regional hospitals. Patients and Methods: Patients with suspected acute malignant large bowel obstruction due to colonic adenocarcinoma will be identified and followed. Analysis will be performed on an intention-to-treat basis. Descriptive statistics of the study cohort will be presented. Primary endpoints will be subjected to multivariate analyses adjusted for confounders. Main Outcome Measures: 30-day severe morbidity (Clavien–Dindo > 3a), 30- and 90-day mortality rates, and overall survival after three and five years. Sample Size: We aim to include 1000 patients, with an interim analysis after the recruitment of 500 patients. Results: The study is ongoing. Conclusions: Acute colon obstruction is associated with substantial morbidity and mortality. We hypothesize that patients with malignant obstruction benefit from avoidance of emergency cancer resection and that bridge to surgery leads to decreased short-term morbidity and mortality and improved long-term oncological outcomes. Limitations: The main limitation is the risk of selection bias when the study is not a randomized controlled trial, which would be a standard process. A prospective observational study is, nevertheless, considered a pragmatic compromise between feasibility and ability to answer the research question. Conflicts of Interest: None.