Surveillance guidelines after removal of colorectal adenomatous polyps
- 1Cancer Research UK Colorectal Cancer Unit, St Mark’s Hospital, Harrow, Middlesex HA1 3UJ, UK
- 2Wolfson Unit for Endoscopy, St Mark’s Hospital
- Correspondence to:
Dr W Atkin;
Most colon cancers are assumed to have a premalignant adenomatous polyp phase, therefore colonoscopic detection and polypectomy provides the opportunity for cancer prevention. Some patients who have undergone colonoscopy and have had adenomas removed are at increased risk of developing colorectal cancer (CRC) in the future, and therefore might benefit from colonoscopic surveillance. However, it is important to appreciate that colonoscopy is an invasive and costly procedure with some associated morbidity. It is also an under-resourced procedure in the UK, with a serious lack of fully trained endoscopists. Around one third of the population will develop an adenoma by age 60. Most adenomas are asymptomatic and remain undiagnosed. If colorectal screening is introduced this situation will change dramatically. There are few data on the benefits of colonoscopic surveillance in preventing colorectal cancer after a baseline clearing colonoscopy. It is therefore important that this practice is applied judiciously, balancing the risks and benefits in each individual case. Using published evidence, this guideline recommends appropriate surveillance after adenoma removal. The decision to perform each follow up colonoscopy should also depend on the patient’s wishes, the presence of comorbidity, the patient’s age, and the presence of other risk factors.
Risk of colorectal cancer and adenomas with advanced pathology (≥1 cm or severely dysplastic) (see fig 1)
Risk can be stratified according to findings at baseline and refined at each subsequent surveillance examination. (Recommendation Grade B)
Patients with only 1–2, small (<1 cm) adenomas.
Recommendation: no follow up or five yearly until one negative examination.
Patients with 3–4 small adenomas or at least one >1 cm
Recommendation: three yearly until two consecutive negative examinations.
If either of the following are detected at any single examination (at baseline or follow up):
≥5 adenomas or ≥3 adenomas at least one of which is ≥1 cm.
Recommendation: An extra examination should be undertaken at 12 months before returning …