Introduction Subjects who have an abnormal FOBt within the Bowel Cancer Screening Programme (BCSP) are offered surveillance following their initial index colonoscopy (IC) in line with National Guidance. High risk (1 year surveillance): 5 or more adenomas or 3 adenomas including one >1 cm. Medium risk (3 year surveillance): one adenoma > 1 cm or 3–4 adenomas. Low risk (No surveillance, but sent a further FOBt kit in 2 years): less than 3 adenomas. The aim of this study was to document the colonoscopic findings in individuals who attended for more than one IC within the BCSP.
Method All subjects who had a colonoscopy within the BCSP between the period 1/10/2007 to 31/1/2015 were identified from the endoscopy database (Scorpio). This dataset was refined to include only subjects in whom the initial colonoscopy did not satisfy the criteria for surveillance. These reports were examined to confirm subsequent procedures were a consequence of a further abnormal FOBt and the findings for all procedures on these individuals were recorded.
Results 3653 ICs were performed within the study period. 64 subjects (1.8%) satisfied the entry criteria. 58 (90.6%) subjects had a second IC after 2 years and 6 (9.4%) subjects after 4 years. 3 (4.7%) subjects had 2 further examinations at 2 and 4 years. The findings from the second IC in all subjects are shown in the Table 1below.
19 subjects (29.7%) had low risk findings at the second IC and 8 subjects (12.5%) had medium risk findings, triggering surveillance. In 7 of these 3 or more adenomas were found, but 1 subject had a 1 cm adenoma after a normal IC. No patients had high risk findings. Adenomas were found more commonly at the second IC in subjects with adenomas at the first IC, compared to individuals with no adenomas at the first IC, (p < 0.05 Fishers Exact Test). In the 3 patients who had a third IC, 2 had no adenomas, one following a normal examination and one following a low risk examination. One subject had low risk findings after a previous low risk examination.
Conclusion Approximately 2% of subjects within the BCSP underwent 2 or more ICs. High risk findings were not seen in this cohort, suggesting that ceasing screening for subjects with a low risk first IC will not result in the early development of malignancy. However, 42.2% of subjects had adenomas removed at subsequent examinations, conferring potential benefits for future cancer prevention. This presumed benefit needs to be balanced against the increased workload of offering recurrent FOB testing, particularly in the context of the increasing pressure within the BCSP from the introduction of Bowel Scope and possibly FIT.
Disclosure of interest None Declared.