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

Amanda J Cross,Karen G Flashman,Kevin Pack,Brian P Saunders,Wendy Atkin,Margaret Vance,Michael R Thompson,Jeremy P Brown,Kate Wooldrage,Steve Halligan,Emma C Robbins,William Hamilton,Siwan Thomas-Gibson

doi:10.1038/s41416-018-0335-z

Abstract

BackgroundPatients 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.MethodsCohort 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).ResultsOne 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.ConclusionMost 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.

Highlights

Patients referred to hospital with suspected colorectal cancer (CRC) typically undergo whole-colon investigation (WCI), predominantly colonoscopy or computed tomography (CT) colonography, in line with National Institute for Health and Care Excellence (NICE) guidelines.[1]
Very few proximal cancers were detected in patients without anaemia and/or abdominal mass who presented with rectal bleeding, alone or with other symptoms/signs. These novel findings led us to conclude that flexible sigmoidoscopy alone is sufficient for patients without . anaemia and/or abdominal mass who present with any rectal bleeding or solely a change in bowel habit (CIBH) to increased frequency, unless there are significant distal findings that warrant WCI or the examination is incomplete
163 CONCLUSION Our findings confirm the strong association between anaemia and proximal cancer, with 80% of proximal cancer patients in our cohort meeting the criteria for broad definition anaemia

Summary

Introduction

Patients referred to hospital with suspected colorectal cancer (CRC) typically undergo whole-colon investigation (WCI), predominantly colonoscopy or computed tomography (CT) colonography, in line with National Institute for Health and Care Excellence (NICE) guidelines.[1] In 2015, NICE issued a guideline on referral criteria, including symptoms and signs conferring a positive predictive value for cancer of 3%.2. 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. 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

Methods

Results

Discussion

Conclusion