Morbidity and mortality following major large bowel resection for colorectal cancer detected by a population-based screening program

Background and Aims — In 2008, Ontario initiated a population-based colorectal screening program using guaiac fecal occult blood testing. This work was undertaken to fill a major gap in knowledge by estimating serious post-operative complications and mortality following major large bowel resection of colorectal cancer detected by a population-based screening program.

Methods — We identified persons with a first positive fecal occult blood result between 2008 and 2016, at the age of 50–74 years, who underwent a colonoscopy within 6 months, and proceeded to major large bowel resection for colon cancer within 6 months or rectosigmoid/rectal cancer within 12 months, and identified an unscreened cohort of resected cases diagnosed during the same years at the age of 50–74 years. We identified serious postoperative complications and readmissions ≤30 days following resection, and postoperative mortality ≤30 days, and between 31 and 90 days among the screen-detected and the unscreened cohorts.

Results — Serious post-operative complications or readmissions within 30 days were observed among 1476/4999 (29.5%) cases in the screen-detected cohort, and among 3060/8848 (34.6%) unscreened cases. Mortality within 30 days was 43/4999 (0.9%) among the screen-detected cohort, and 208/8848 (2.4%) among the unscreened cohort. Among 30 day survivors, mortality between 31 and 90 days was 28/4956 (0.6%) and 111/8640 (1.3%), respectively.

Conclusion — Serious post-operative complications, readmissions, and mortality may be more common following major large bowel resection for colorectal cancer between the ages of 50 and 74 among unscreened compared to screen-detected cases.