Whole-colon investigation vs. flexible sigmoidoscopy for suspected colorectal cancer based on presenting symptoms and signs: a multicentre cohort study

Abstract

Background Patients with suspected colorectal cancer (CRC) usually undergo colonoscopy. Flexible sigmoidoscopy (FS) may be preferred if proximal cancer risk is low. We investigated which patients could undergo FS alone. Methods Cohort study of 7375 patients (≥55 years) referred with suspected CRC to 21 English hospitals (2004–2007), followed using hospital records and cancer registries. We calculated yields and number of needed whole-colon examinations (NNE) to diagnose one cancer by symptoms/signs and subsite. We considered narrow (haemoglobin <11 g/dL men; <10 g/dL women) and broad (<13 g/dL men; <12 g/dL women) anaemia definitions and iron-deficiency anaemia (IDA). Results One hundred and twenty-seven proximal and 429 distal CRCs were diagnosed. A broad anaemia definition identified 80% of proximal cancers; a narrow definition with IDA identified 39%. In patients with broad definition anaemia and/or abdominal mass, proximal cancer yield and NNE were 4.8% (97/2022) and 21. In patients without broad definition anaemia and/or abdominal mass, with rectal bleeding or increased stool frequency (41% of cohort), proximal cancer yield and NNE were 0.4% (13/3031) and 234. Conclusion Most proximal cancers are accompanied by broad definition anaemia. In patients without broad definition anaemia and/or abdominal mass, with rectal bleeding or increased stool frequency, proximal cancer is rare and FS should suffice.

Using the faecal immunochemical test in patients with rectal bleeding: evidence from the NICE FIT study

“…While RB is considered a ‘red flag’ symptom for CRC indicating urgent investigation, in fact RB is caused by an underlying CRC in less than 5% of patients referred for colonoscopy [13]. In patients with RB, CRC beyond the splenic flexure is rare and in the absence of anaemia or an abdominal mass an argument may be made for investigation with flexible sigmoidoscopy alone [18]. However, utilization of flexible sigmoidoscopy to investigate all patients with RB would not detect 10% of CRC in our data.…”

Colonoscopy and flexible sigmoidoscopy for follow-up of patients with left-sided diverticulitis

“…There are many conflicts between studies on the benefits of performing endoscopy after a diagnosis with diverticulitis, with many reviewed studies drawing the conclusion that endoscopy can be omitted after an episode of uncomplicated diverticulitis. [7][8][9][10][11][12] However, it can be beneficial in cases of complicated diverticulitis or continuing symptoms, and in patients aged over 70 years, because the risk of malignancy in these patients is higher. [7][8][9]13 In contrast, the Association of Coloproctology of Great Britain and Ireland (ACPGBI) has recommended that all patients require investigation of the colonic lumen by endoscopy, barium enema or CT colonography after the acute attack of diverticulitis has resolved.…”

Increasing rate of colorectal cancer in younger patients: a review of colonoscopy findings in patients under 50 at a tertiary institution

“…It is argued that in young patients with no other risk factor, there is a low risk of proximal cancer, hence flexible sigmoidoscopy will have a low risk of missing significant lesions. [24][25][26][27][28] It also offers a quicker and safer procedure that does not require complete bowel preparation. However, in our study 36.4% of cancers were right sided.…”

“…In young patients some have advocated for a flexible sigmoidoscopy in the investigation of PR bleeding. It is argued that in young patients with no other risk factor, there is a low risk of proximal cancer, hence flexible sigmoidoscopy will have a low risk of missing significant lesions 24–28 . It also offers a quicker and safer procedure that does not require complete bowel preparation.…”