Introduction: Background Colorectal cancer (CRC) is the 4th most common cancer in UK. Most CRC arise in adenoma and removal of adenoma reduces the risk of colorectal cancer. Colonoscopy is considered gold standard for detection of adenomatous polyps.Most societies recommend counselling patients undergoing colonoscopy about a miss rate of 2.1% to 5.9% for significant polyp/cancers.
Method Aim: a). Audit post-colonoscopy CRC as per auditable outcome of UK key performance indicators for Colonoscopy. 1 b). This is a repeat audit to ensure standards are maintained as well as expanding on recommendations made to us by the BSG assessors at the 2012 BSG conference, to include polyps, which they felt were a more relevant benchmark regarding missed pathology in the time frame. 2
Data of all patients who had colonoscopy in 2010 (January to end of December) and repeat colonoscopy in the next five years was collected from hospital database. Polyp ≥1 cm was defined as significant polyp.
Results Total 1242 patients underwent colonoscopy in 2010 while 440 patients had repeat colonoscopy in the next five years. Cancer miss rate was 1.13% (5/440), while significant polyp miss rate was 5.45% (24/440). 4 out of 5 missed CRC were left sided while significant polyps were missed throughout the colon.
Conclusion The data shows that our post colonoscopy CRC rate remains low i-e 1.13% (target of <5% at 3 years per KPI standards) and polyps missed rate remains similar to published studies. 80% of cancers were on the left side of the colon, whereas the distribution of polyps was evenly split i-e no correlation between sites of polyp and cancers.
Poor bowel prep contributed to missed pathology in 1 case and are no longer accepted as acceptable and are repeated.The unit will also be auditing colonoscopy withdrawl times.
Polyps were reported/treated in the same area where cancer was later diagnosed in 2 cases therefore diligent examination of previous pathology site is important.
. Rees CJ, et al. UK key performance indicators and quality assurance standards for colonoscopy. Gut2016.
. Somasundaram CS, et al. Post colonoscopy cancers in 5-year interval. Gut2012.
Disclosure of Interest None Declared