Anu E Obaro1, Andrew A Plumb2, Thomas R Fanshawe3, Ulysses S Torres4, Rachel Baldwin-Cleland5, Stuart A Taylor6, Steve Halligan6, David N Burling5. 1. Centre for Medical Imaging, University College London, London, UK; St Mark's Academic Institute, St Mark's Hospital, Harrow, London, UK. 2. Centre for Medical Imaging, University College London, London, UK. Electronic address: andrew.plumb@ucl.ac.uk. 3. Nuffield Department of Primary Care Health Sciences, Oxford University, Oxford, UK. 4. Grupo Fleury, São Paulo, Brazil. 5. St Mark's Academic Institute, St Mark's Hospital, Harrow, London, UK. 6. Centre for Medical Imaging, University College London, London, UK.
Abstract
BACKGROUND: CT colonography is highly sensitive for colorectal cancer, but interval or post-imaging colorectal cancer rates (diagnosis of cancer after initial negative CT colonography) are unknown, as are their underlying causes. We did a systematic review and meta-analysis of post-CT colonography and post-imaging colorectal cancer rates and causes to address this gap in understanding. METHODS: We systematically searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. We included randomised, cohort, cross-sectional, or case-control studies published between Jan 1, 1994, and Feb 28, 2017, using CT colonography done according to international consensus standards with the aim of detecting cancer or polyps, and reporting post-imaging colorectal cancer rates or sufficient data to allow their calculation. We excluded studies in which all CT colonographies were done because of incomplete colonoscopy or if CT colonography was done with knowledge of colonoscopy findings. We contacted authors of component studies for additional data where necessary for retrospective CT colonography image review and causes for each post-imaging colorectal cancer. Two independent reviewers extracted data from the study reports. Our primary outcome was prevalence of post-imaging colorectal cancer 36 months after CT colonography. We used random-effects meta-analysis to estimate pooled post-imaging colorectal cancer rates, expressed using the total number of cancers and total number of CT colonographies as denominators, and per 1000 person-years. This study is registered with PROSPERO, number CRD42016042437. FINDINGS: 2977 articles were screened and 12 studies were eligible for analysis. These studies reported data for 19 867 patients (aged 18-96 years; of 11 590 with sex data available, 6532 [56%] were female) between March, 2002, and May, 2015. At a mean of 34 months' follow-up (range 3-128·4 months), CT colonography detected 643 colorectal cancers. 29 post-imaging colorectal cancers were subsequently diagnosed. The pooled post-imaging colorectal cancer rate was 4·42 (95% CI 3·03-6·42) per 100 cancers detected, corresponding to 1·61 (1·11-2·33) post-imaging colorectal cancers per 1000 CT colonographies or 0·64 (0·44-0·92) post-imaging colorectal cancers per 1000 person-years. Heterogeneity was low (I2=0%). 17 (61%) of 28 post-imaging colorectal cancers were attributable to perceptual error and were visible in retrospect. INTERPRETATION: CT colonography does not lead to an excess of post-test cancers relative to colonoscopy within 3-5 years, and the low 5-year post-imaging colorectal cancer rate confirms that the recommended screening interval of 5 years is safe. Since most post-imaging colorectal cancers arise from perceptual errors, radiologist training and quality assurance could help to reduce post-imaging colorectal cancer rates. FUNDING: St Mark's Hospital Foundation and the UK National Institute for Health Research via the UCL/UCLH Biomedical Research Centre.
BACKGROUND: CT colonography is highly sensitive for colorectal cancer, but interval or post-imaging colorectal cancer rates (diagnosis of cancer after initial negative CT colonography) are unknown, as are their underlying causes. We did a systematic review and meta-analysis of post-CT colonography and post-imaging colorectal cancer rates and causes to address this gap in understanding. METHODS: We systematically searched MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials. We included randomised, cohort, cross-sectional, or case-control studies published between Jan 1, 1994, and Feb 28, 2017, using CT colonography done according to international consensus standards with the aim of detecting cancer or polyps, and reporting post-imaging colorectal cancer rates or sufficient data to allow their calculation. We excluded studies in which all CT colonographies were done because of incomplete colonoscopy or if CT colonography was done with knowledge of colonoscopy findings. We contacted authors of component studies for additional data where necessary for retrospective CT colonography image review and causes for each post-imaging colorectal cancer. Two independent reviewers extracted data from the study reports. Our primary outcome was prevalence of post-imaging colorectal cancer 36 months after CT colonography. We used random-effects meta-analysis to estimate pooled post-imaging colorectal cancer rates, expressed using the total number of cancers and total number of CT colonographies as denominators, and per 1000 person-years. This study is registered with PROSPERO, number CRD42016042437. FINDINGS: 2977 articles were screened and 12 studies were eligible for analysis. These studies reported data for 19 867 patients (aged 18-96 years; of 11 590 with sex data available, 6532 [56%] were female) between March, 2002, and May, 2015. At a mean of 34 months' follow-up (range 3-128·4 months), CT colonography detected 643 colorectal cancers. 29 post-imaging colorectal cancers were subsequently diagnosed. The pooled post-imaging colorectal cancer rate was 4·42 (95% CI 3·03-6·42) per 100 cancers detected, corresponding to 1·61 (1·11-2·33) post-imaging colorectal cancers per 1000 CT colonographies or 0·64 (0·44-0·92) post-imaging colorectal cancers per 1000 person-years. Heterogeneity was low (I2=0%). 17 (61%) of 28 post-imaging colorectal cancers were attributable to perceptual error and were visible in retrospect. INTERPRETATION: CT colonography does not lead to an excess of post-test cancers relative to colonoscopy within 3-5 years, and the low 5-year post-imaging colorectal cancer rate confirms that the recommended screening interval of 5 years is safe. Since most post-imaging colorectal cancers arise from perceptual errors, radiologist training and quality assurance could help to reduce post-imaging colorectal cancer rates. FUNDING: St Mark's Hospital Foundation and the UK National Institute for Health Research via the UCL/UCLH Biomedical Research Centre.
Authors: Kevin J Monahan; Michael M Davies; Muti Abulafi; Ayan Banerjea; Brian D Nicholson; Ramesh Arasaradnam; Neil Barker; Sally Benton; Richard Booth; David Burling; Rachel Victoria Carten; Nigel D'Souza; James Edward East; Jos Kleijnen; Michael Machesney; Maria Pettman; Jenny Pipe; Lance Saker; Linda Sharp; James Stephenson; Robert Jc Steele Journal: Gut Date: 2022-07-12 Impact factor: 31.793
Authors: Matthew D Rutter; James East; Colin J Rees; Neil Cripps; James Docherty; Sunil Dolwani; Philip V Kaye; Kevin J Monahan; Marco R Novelli; Andrew Plumb; Brian P Saunders; Siwan Thomas-Gibson; Damian J M Tolan; Sophie Whyte; Stewart Bonnington; Alison Scope; Ruth Wong; Barbara Hibbert; John Marsh; Billie Moores; Amanda Cross; Linda Sharp Journal: Gut Date: 2019-11-27 Impact factor: 31.793
Authors: Natalia Calanzani; Aina Chang; Marije Van Melle; Merel M Pannebakker; Garth Funston; Fiona M Walter Journal: Adv Ther Date: 2021-04-17 Impact factor: 3.845
Authors: Laura J Neilson; Linda Sharp; Joanne M Patterson; Christian von Wagner; Paul Hewitson; Lesley M McGregor; Colin J Rees Journal: BMJ Open Gastroenterol Date: 2021-10
Authors: Laura J Neilson; Joanne Patterson; Christian von Wagner; Paul Hewitson; Lesley M McGregor; Linda Sharp; Colin J Rees Journal: Frontline Gastroenterol Date: 2020-01-13
Authors: Cristiano Spada; Cesare Hassan; Davide Bellini; David Burling; Giovanni Cappello; Cristina Carretero; Evelien Dekker; Rami Eliakim; Margriet de Haan; Michal F Kaminski; Anastasios Koulaouzidis; Andrea Laghi; Philippe Lefere; Thomas Mang; Sebastian Manuel Milluzzo; Martina Morrin; Deirdre McNamara; Emanuele Neri; Silvia Pecere; Mathieu Pioche; Andrew Plumb; Emanuele Rondonotti; Manon Cw Spaander; Stuart Taylor; Ignacio Fernandez-Urien; Jeanin E van Hooft; Jaap Stoker; Daniele Regge Journal: Eur Radiol Date: 2021-05 Impact factor: 5.315