Introduction St Mark's Bowel Cancer Screening Centre (BCSC) was one ofthe first English screening centres rolled out between Oct 2006-Nov 2007. We report the preliminary experience of St Mark's BCSC over the first 35 months of screening.

Methods To review the outcomes of 1488 screening participants referred following positive FOBT. Those unfit for colonoscopy were offered alternatives such as CT Virtual Colonoscopy (VC). Data regarding gender, age, colonoscopy findings and screening outcomes were analysed.

Results 98 815 FOBT kits were sent out and 42 523 returned (43% uptake).1488 positive FOBT participants were referred to the nurse clinic. 1339 (90%) attended. 57% were men. 1138 (85%) were suitable for colonoscopy, 122 (9%) for VC and 17 (1%) for flexible sigmoidoscopy. 62 (5%) were not referred further on medical grounds. 1057 (79%) screenees underwent first procedure colonoscopy, 115 had a VC and eight had a flexible sigmoidoscopy. 514 (44%) procedures were “normal”, 583 (50%) patients had polyps (155 (26%) high risk, 170 (29%) intermediate risk and 258 (45%) low risk polyps). In 583 patients with polyps, 1625 polyps were found (average 2.8 polyps per patient). 96% were adenomas. Median polyp size was 5 mm (1–80). 74 patients (6%) had colorectal cancer. Three patients had non-colonic incidental cancers. Overall, 1200 colonoscopies were performed by five screeners until September 2009 (1057 first procedure colonoscopies, 82 repeat colonoscopies, 61 surveillance procedures), with a 96% completion rate. There was one 30-day post surgical mortality.

Conclusion Over the period reviewed, >1200 colonoscopies were performed with excellent (96%) completion rates. Significant pathology (cancers and polyps) was found in 45% of patients with a positive FOBT. Despite the polyp/adenoma detection rates being higher than those expected, cancer rates were lower than national figures. This was possibly due to a previous flexible sigmoidoscopy trial in the centre in 1999.