The 'obesity paradox' and survival after colorectal cancer: true or false?
AuthorsRenehan, Andrew G
AffiliationDepartment of Surgery, Institute of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK, firstname.lastname@example.org.
MetadataShow full item record
AbstractBody mass index (BMI), as an approximation of general adiposity, is an established risk factor for incidence of several adult cancer types, including colorectal cancer (CRC). There is a common perception that these relationships extrapolate directly as adverse prognostic factors after diagnosis, but evidence for this is lacking. The paper from Sclesinger et al. in this issue of the journal adds a new dimension to this debate focusing on relationships of post-diagnosis BMI (as a marker of the steady-state weight among survivors) and survival, and provides evidence on a decreased mortality risk among overweight (post-diagnosis BMI 25.0-29.9 kg/m(2)) compared with normal weight (post-diagnosis BMI 18.5-24.9 kg/m(2)) CRC survivors-an example of an 'obesity paradox.' The observation of the 'obesity paradox' is well documented in the methodology literature, but perhaps, less familiar to the cancer readership. Three broad classes of explanation are posited: (1) the associations are true and plausible; (2) the associations are false and reflect methodological issues; or (3) the observations represent a specific form of selection bias, known as collider bias. The present author argues that the obesity paradox reflects the latter-a product of a statistical bias-and emphasizes that, while these findings are hypothesis generating, they will not alter clinical practice or recommendations.
CitationThe 'obesity paradox' and survival after colorectal cancer: true or false? 2014: Cancer Causes Control
JournalCancer Causes & Control
- Postdiagnosis body mass index and risk of mortality in colorectal cancer survivors: a prospective study and meta-analysis.
- Authors: Schlesinger S, Siegert S, Koch M, Walter J, Heits N, Hinz S, Jacobs G, Hampe J, Schafmayer C, Nöthlings U
- Issue date: 2014 Oct
- Analysis of Body Mass Index and Mortality in Patients With Colorectal Cancer Using Causal Diagrams.
- Authors: Kroenke CH, Neugebauer R, Meyerhardt J, Prado CM, Weltzien E, Kwan ML, Xiao J, Caan BJ
- Issue date: 2016 Sep 1
- The Obesity Paradox in Cancer: a Review.
- Authors: Lennon H, Sperrin M, Badrick E, Renehan AG
- Issue date: 2016 Sep
- A paradox between preoperative overweight/obesity and change in weight during postoperative chemotherapy and its relationship to survival in stage Ⅱ and Ⅲ colorectal cancer patients.
- Authors: Hu C, Zhang Q, Jin X, Zhang L, Zhang Y, Zhu Q, Tang M, Lyv G, Shi H
- Issue date: 2021 Apr
- Prognostic relevance of prediagnostic weight loss and overweight at diagnosis in patients with colorectal cancer.
- Authors: Walter V, Jansen L, Hoffmeister M, Ulrich A, Roth W, Bläker H, Chang-Claude J, Brenner H
- Issue date: 2016 Oct