Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Bowel polyps are small, benign (harmless) growths found on the inner lining of the colon (end part of the large intestine) or rectum. They are not usually cancerous, however if they are found they should be removed as some will eventually turn into cancer if left untreated. People who have been found to have bowel polyps need to undergo colposcopies in order to monitor the growth of polyps and check for new ones. This involves having a thin, flexible tube with a camera on the end being inserted into the anus to look at the lining of the large intestine. The aim of this study is to find out how often these colonoscopies should take place to best monitor patients with bowel polyps to prevent the development of cancer.

Who can participate?
Patients aged between 20 and 71 attending St Mark’s Hospital between 1979-1990 with bowel polyps or bowel cancer.

What does the study involve?
Patients are divided into groups depending on their risk of developing bowel cancer. Those who have a high risk are randomly allocated to undergo colonoscopies at 12-18 month intervals or every three years. Those who have a low risk are randomly allocated to undergo examinations every three years or every five years. Throughout the study, all patients are monitored for the development of bowel cancer and at the end of the study, the best possible frequency of monitoring is determined.

What are the possible benefits and risks of participating?
Not provided at time of registration

Where is the study run from?
Imperial College London (UK)

When is the study starting and how long is it expected to run for?
January 1979 to January 1990

Who is funding the study?
1. National Institute for Health Research, Health Technology Assessment Programme (UK)
2. Cancer Research UK (UK)

Who is the main contact?
Professor Wendy Atkin

Trial website

Contact information



Primary contact

Prof Wendy S Atkin


Contact details

Imperial College London
St. Mary's Campus
Norfolk Place
W2 1PG
United Kingdom
+44 20 7594 3369

Additional identifiers

EudraCT number number

Protocol/serial number

HTA 04/33/01

Study information

Scientific title

Randomised trial of colonoscopic surveillance intervals after removal of colorectal adenomas


Study hypothesis

The study was designed to compare the effectiveness of different frequencies of colonoscopic examination, with polypectomy of all adenomas detected, for preventing advanced adenomas and colorectal cancer (CRC).

A secondary aim of this study was to identify baseline risk factors for diagnosis of advanced neoplasia (adenomas and CRC) during follow-up. This approach was adopted to determine if a subgroup of patients might benefit from more intense surveillance.

Ethics approval

Not applicable because ethical approval standards were not in place when the study was started in the late 1970s – early 1980s.

Study design

Single-centre stratified randomised trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

No participant information sheet available


Colorectal cancer


Study of colonoscopic surveillance regimens. Allocation to regimen was by minimisation method. Patients were stratified into high and low risk groups by their characteristics at entry (age, malignancy and multiplicity of adenomas). Then within the high risk group the participants could be randomised to frequent follow-up or exams at three year intervals. Within the low risk group paricipants could be randomised to exams at three year intervals or exams at five year intervals. No masking, all participants received surveillance.

High risk patients:
Three exams at 12-18 month intervals and 3-yearly follow-up thereafter (median endoscopic surveillance - 7.0 yrs, median passive follow-up - 18.6 yrs) or exams at three year intervals (median endoscopic surveillance - 6.6 yrs, median passive follow-up - 18.8 yrs)

Low risk patients:
Exams at three year intervals (median endoscopic surveillance - 9.1 yrs, median passive follow-up - 21.7 yrs) or exams at five year intervals (median endoscopic surveillance - 6.3 yrs, median passive follow-up - 21.8 yrs)

Intervention type



Not Applicable

Drug names

Primary outcome measure

The primary outcome was the diagnosis of advanced neoplasia (advanced adenomas or colorectal cancer) during follow-up. An advanced adenoma was defined as an adenoma ≥ 10 mm or with high grade dysplasia.

Secondary outcome measures

Detection of any adenoma during follow-up.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Patients attending St Mark’s Hospital between 1979-1990, with endoscopically removed adenomas or malignant lesions
2. 468 males and 317 females in the study, aged between 20 and 71

Participant type


Age group




Target number of participants

785 patients were recruited

Participant exclusion criteria

1. History of inflammatory bowel disease
2. Surgical resection for CRC
3. A rectal villous adenoma
4. Patients older than 70 years

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Imperial College London
W2 1PG
United Kingdom

Sponsor information


Imperial College London

Sponsor details

Clinical Research Governance Office
Sir Alexander Fleming Building
South Kensington Campus
United Kingdom
+44 (0)20 7594 1554

Sponsor type




Funder type


Funder name

Health Technology Assessment Programme

Alternative name(s)

NIHR Health Technology Assessment Programme, HTA

Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government


United Kingdom

Funder name

Cancer Research UK

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype

other non-profit


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1992 results in

Publication citations

Additional files

Editorial Notes

02/03/2017: A plain English summary has been added. Publication reference added. 04/03/2016: No publications found, verifying study status with principal investigator.