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PTH-039 Prevalence of sessile serrated adenomas/polyps in distal colon during screening colonoscopy/flexible sigmoidoscopy: a single bowel cancer screening experience from uk
  1. R Rameshshanker1,
  2. F Purchiaroni,
  3. W Ana,
  4. S Thomas-Gibson,
  5. A Rajendran,
  6. BP Saunders,
  7. Z Tsiamoulos
  1. Wolfson Unit for Endoscopy, St Mark’s Hospital, London, UK


Introduction Sessile Serrated Adenomas/Polyps (SSA/P) are responsible for nearly 20% of colo rectal cancer (CRC). Despite the utility of novel image enhancing techniques including narrow band imaging it is difficult to differentiate hyperplastic (HP) polyps from SSA/Ps. Vast proportion of endoscopists leave the diminutive and possibly small HP polyps in situ in the recto sigmoid area (diagnose and disregard approach). Hence there is a possibility of leaving SSA/P in the recto sigmoid region which could potentially lead to CRC later in life.

Aim To estimate the prevalence of SSA/P in recto sigmoid colon at screening colonoscopy and flexible sigmoidoscopy (FS).

Method Patients aged >55 years underwent a screening colonoscopy (n=500) or a flexible sigmoidoscopy (n=500) at our institution between August 2014 and April 2015 were included. Data collected from 500 consecutive patients who underwent a colonoscopy or a FS. Demographic, procedural and polyp data were retrieved from our endoscopy database.

Results 99.6% of (498/500) colonoscopy and 97.6% of flexible sigmoidoscopy procedures were completed. Screening colonoscopy detected 1006 polyps and FS detected 249 polyps. Polyp size ranged between 1–80 mm (colonoscopy mean size 6 mm, SD 7.2 mm; FS mean 3.4 mm, SD 3.9 mm). While colonoscopy detected 43 SSA/Ps (4.3%), FS detected only 6 SSA/Ps (2.4%) which equates to an overall prevalence of 3.9% (49/1255). Image 1 summarises the SSA/Ps prevalence by colonic segment. In recto sigmoid there were 21 SSA/Ps detected and resected which equals to a 3.9% of all recto sigmoid polyps. All SSA/Ps detected in this segment were less than 10 mm in size (range 2–10 mm). Only one of the SSA/P had dysplasia (4.7%). Prevalence of SSA/Ps in proximal colon was 4.8%.

Conclusion Our cohort showed a slightly higher prevalence of SSA/Ps in rectum and sigmoid colon. Therefore, it becomes clinically relevant to differentiate SSA/Ps from HP polyps in recto sigmoid before adapting a diagnose and disregard approach for small (<9 mm) hyperplastic looking polyps in this location.

Disclosure of Interest None Declared

  • adenoma
  • Advanced adenoma
  • sessile serrated polyps

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