Abstract
BACKGROUND:
Although young-age-of-onset colorectal cancer is increasing in incidence, lack of screening leads to symptomatic presentation, often with rectal bleeding. Because most cancers in patients younger than 50 years are left-sided, flexible sigmoidoscopy is a reasonable way of investigating bleeding in these patients.
OBJECTIVE:
To predict which patients undergoing flexible sigmoidoscopy for outlet-type rectal bleeding need a full colonoscopy.
DESIGN:
Findings at colonoscopy were compared with published indications for colonoscopy after flexible sigmoidoscopy, which were as follows: 1) any number of advanced adenomas defined as a tubular adenoma of >9 mm diameter, a tubulovillous or villous adenoma of any size, or any adenoma with high-grade dysplasia; 2) 3 or more tubular adenomas of any size or histology; 3) any sessile serrated lesion; and 4) 20 or more hyperplastic polyps.
SETTING:
Charity Hospital with volunteer specialists.
PATIENTS:
Patients were included if they were younger than 57 years, had outlet-type rectal bleeding, and underwent flexible sigmoidoscopy at least to the descending colon followed by colonoscopy with biopsy of all resected lesions.
INTERVENTIONS:
Flexible sigmoidoscopy and colonoscopy with excision of all removable lesions.
MAIN OUTCOME MEASURES:
Findings at colonoscopy.
RESULTS:
There were 66 patients who had a colonoscopy between 5 and 811 days after sigmoidoscopy and also had complete data. There were 43 men and 23 women with a mean age of 39.5 years. Analysis of flexible sigmoidoscopy criteria for finding proximal high-risk lesions on colonoscopy showed a sensitivity of 76.9%, a specificity of 67.9%, a positive predictive value of 37%, a negative predictive value of 92.3%, and an accuracy of 69.7%.
LIMITATIONS:
A large number of exclusions for inadequate colonoscopy or inadequate data resulted in a reduced patient number in the study.
CONCLUSIONS:
Our criteria for follow-up colonoscopy based on the findings at initial flexible sigmoidoscopy in young patients with outlet-type rectal bleeding are reliable enough to be used in routine clinical practice, provided this is audited.
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(C) The ASCRS 2023