# UK Flexible Sigmoidoscopy Screening Trial

Source: https://onco.cc/trials/ukfss/  
OnCo record `ukfss` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The trial that showed one look inside the lower bowel in your late fifties can prevent a bowel cancer for life, and that a single test is enough.

## Summary

The UK Flexible Sigmoidoscopy Screening Trial offered 57,237 people a single flexible sigmoidoscopy between 55 and 64 and compared them with 113,195 who were not contacted. Seven in ten attended. After a median 11.2 years, colorectal cancer incidence in the invited group was 23 percent lower (hazard ratio 0.77, 0.70 to 0.84) and mortality 31 percent lower (0.69, 0.59 to 0.82); among those who actually attended, incidence fell 33 percent and mortality 43 percent, and incidence of distal cancer halved. The 17-year follow-up published in 2017 showed the benefit persisted. The result created Bowel Scope Screening in England, which was later withdrawn in favour of extending the faecal immunochemical test programme down to age 50; NHS England confirmed in January 2021 that bowel scope is no longer offered.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-24
- Also known as: UKFSST; ISRCTN28352761
- Tags: uk; screening; colorectal
- Registry id: ISRCTN28352761
- Phase: 3
- Setting: A single flexible sigmoidoscopy between the ages of 55 and 64, offered once, against no contact; 14 UK centres, 170,432 people who had said they would accept an invitation, recruited from July 1995
- Sponsor: Imperial College London with the Medical Research Council
- Enrolled: 170432
- Result: Colorectal cancer incidence 23 percent lower and mortality 31 percent lower in those invited to a single flexible sigmoidoscopy (33 percent and 43 percent among attenders); the 17-year follow-up confirmed the effect lasted.

## Sources

- Lancet 2010: https://europepmc.org/article/MED/20430429
- Lancet 2017: 17-year follow-up: https://europepmc.org/article/MED/28236467
- ISRCTN28352761: https://www.isrctn.com/ISRCTN28352761

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/)
- fronts: [Early Detection & Screening](https://onco.cc/fronts/early-detection/), [Prevention & Risk](https://onco.cc/fronts/prevention/)
- technologies: [Colorectal cancer screening (colonoscopy, FIT, stool DNA, blood)](https://onco.cc/technologies/colorectal-screening/)
- institutions: [Imperial College Healthcare NHS Trust / Imperial College London Cancer Research](https://onco.cc/institutions/imperial-cancer-centre/)
- terms: [Colonoscopy](https://onco.cc/terms/colonoscopy/)

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