THE YIELD FROM POLYP SURVEILLANCE AT A BOWELSCREEN CENTRE

Aims Colorectal cancer is the second leading cause of cancer mortality in Ireland. BowelScreen was instituted in 2012 as a cost-effective programme for reducing mortality among the asymptomatic population. As the programme expands, the number of surveillance procedures is increasing without a significant increase in BowelScreen endoscopy capacity.Audit of BowelScreen clients attending the Mater Misericordiae University Hospital (MMUH) to determine volume and yield of surveillance.

Methods The local BowelScreen database was used to review clients assessed at MMUH in 2018. Clients who attended for polyp surveillance were identified and their colonoscopy report history were analysed. Reports were divided into index and surveillance and compared based on polyp number and size.

Results In 2018 there was a 50% rise in patients pre-assessed for surveillance colonoscopy compared to 2017 without a significant rise in index cases performed. 124 clients attended for surveillance colonoscopy. 20 patients underwent more than one round of surveillance since index giving a total of 142 colonoscopies which were included within the scope of this audit. At index colonoscopy, an average of 4.1 polyps were found with 9% being 3 cm or greater, 52% between 1 and 3 cm, 32% between 0.5 and 1 cm and 7% less than 0.5 cm. In comparison, at surveillance an average of 2.1 polyps were identified with 32% of procedures revealing no polyps, 42% showing a polyp < 5 mm and only 6% showing a polyp larger than 1 cm. No interval cancers or polyps greater than 3 cm were diagnosed at surveillance colonoscopy.

Conclusions Surveillance colonoscopy performed in our BowelScreen population yielded half as many polyps with a higher likelihood of smaller uncomplicated polyps. There were no interval large polyps or tumours observed at surveillance. While adenoma surveillance is important, with the growing BowelScreen cohort and limited resources, there may be a role to outsourcing these procedures to non-BowelScreen endoscopy lists.