Components of the full blood count as risk factors for colorectal cancer detection: a systematic review protocol

Pradeep S Virdee; Shona Kirtley; Leena Elhussein; Peter J Watkinson; Tim A Holt; Jacqueline Birks

doi:10.1136/bmjopen-2019-032759

Components of the full blood count as risk factors for colorectal cancer detection: a systematic review protocol

BMJ Open. 2019 Dec 16;9(12):e032759. doi: 10.1136/bmjopen-2019-032759.

Authors

Pradeep S Virdee¹, Shona Kirtley², Leena Elhussein², Peter J Watkinson³, Tim A Holt⁴, Jacqueline Birks²

Affiliations

¹ Centre for Statistics in Medicine, University of Oxford, Oxford, UK pradeep.virdee@csm.ox.ac.uk.
² Centre for Statistics in Medicine, University of Oxford, Oxford, UK.
³ Kadoorie Centre for Critical Care Research and Education, Oxford University Hospitals NHS Trust, Oxford, UK.
⁴ Department of Primary Care Health Sciences, Oxford University, Oxford, UK.

Abstract

Introduction: Colorectal cancer is the fourth most common type of cancer and the second most common cause of cancer-related deaths in the UK. The full blood count (FBC) is a blood test that may play a role in early detection of the disease. Previous studies have aimed to identify how levels of individual components, such as haemoglobin, can be used to assist the diagnosis. We aim to systematically review studies to identify whether components of the FBC are risk factors for diagnosis of colorectal cancer, critically appraise the methods used to assess the association and assess performance of the components.

Methods and analysis: The MEDLINE (via OVID), EMBASE (via OVID), CINAHL (via EBSCOhost) and Web of Science databases will be searched to identify studies reporting the association between the levels of at least one FBC component and the risk of a future diagnosis of colorectal cancer in undiagnosed individuals. Clincialtrials.gov and the WHO registry will be searched to identify relevant ongoing research. Search terms will include relevant Medical Subject Headings and Emtree headings, and free-text terms relating to FBC, colorectal cancer and diagnosis. No date or language restrictions will be applied. Two reviewers will independently identify the studies for inclusion and perform data extraction. Time intervals between the blood tests and diagnosis will form the subgroups for analysis.

Ethics and dissemination: There is no direct patient involvement and only published articles will be reviewed; no ethical approval is required. Results from this review will set a foundation for intended future work on developing a new risk score for early detection of colorectal cancer, derived using FBC data. This systematic review will also provide guidance on the analysis of time to diagnosis. The model will be freely available to UK primary care practices.

Prospero registration number: CRD42019134400.

Keywords: colorectal cancer; complete blood count; early detection; full blood count; risk factor.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Blood Cell Count / standards*
Colorectal Neoplasms / blood*
Colorectal Neoplasms / diagnosis
Early Detection of Cancer / methods
Humans
Risk Factors
Systematic Reviews as Topic

Abstract

Publication types

MeSH terms

Grants and funding