Meta-Analysis
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Apr 26, 2015; 3(2): 125-132
Published online Apr 26, 2015. doi: 10.13105/wjma.v3.i2.125
Red meat intake and the risk of endometrial cancer: Meta-analysis of observational studies
Woong Ju, NaNa Keum, Dong Hoon Lee, Yun Hwan Kim, Seung Cheol Kim, Eric L Ding, Eunyoung Cho
Woong Ju, Yun Hwan Kim, Seung Cheol Kim, Department of Obstetrics and Gynecology, Medical Research Institute, College of Medicine, Ewha Womans University, Seoul 158710, South Korea
NaNa Keum, Dong Hoon Lee, Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, United States
NaNa Keum, Eric L Ding, Department of Nutritron, Harvard School of Public Health, Boston, MA 02115, United States
Eunyoung Cho, Department of Dermatology, the Warren Alpert Medical School of Brown University, Providence, RI 02903, United States
Author contributions: Ju W and Cho E were responsible for the initial plan, study design, conducting the study, data interpretation and manuscript drafting; Ju W, Keum N and Ding EL were responsible for statistical analysis; Ju W, Keum N and Lee DH were responsible for data collection, and data extraction, and data interpretation; Kim YH and Kim SC were responsible for data interpretation and manuscript drafting; Cho E is the guarantor for this paper and has full responsibility for this study.
Supported by A grant of the Korean Health Technology R and D Project, Ministry of Health and Welfare, Republic of Korea, No. HI12C0050.
Conflict-of-interest: All authors have no support from any organization for the submitted work; no financial relationships with any organizations that might have an interest in the submitted work, no other relationships or activities that could appear to have influenced the submitted work.
Data sharing: No additional data available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Eunyoung Cho, ScD, Department of Dermatology, the Warren Alpert Medical School of Brown University, 339 Eddy St, Providence, RI 02903, United States. eunyoung.cho@brown.edu
Telephone: +1-617-5252091 Fax: +1-617-5252008
Received: June 16, 2014
Peer-review started: June 16, 2014
First decision: August 7, 2014
Revised: November 17, 2014
Accepted: February 10, 2015
Article in press: February 12, 2015
Published online: April 26, 2015
Processing time: 315 Days and 23.6 Hours
Abstract

AIM: To evaluate whether red meat intake is related to the risk of endometrial cancer (EC) using meta-analysis.

METHODS: We searched PubMed, EMBASE, and the Cochrane Library up to June 2013, using common keywords related to red meat and EC. Case-control studies and cohort studies comparing the risk of endometrial cancer among categories by the amount of intake were included. Eleven case-control studies and five cohort studies met our criteria. We performed a conventional and a dose-response meta-analysis of case-control studies using the DerSimonian-Laird method for random-effects. For cohort studies we performed a conventional meta-analysis. Publication bias was evaluated using Egger’s test.

RESULTS: In the meta-analysis of 11 case-control studies including 5419 cases and 12654 controls, higher red meat consumption was associated with an increased risk of EC [summary relative risk (SRR) = 1.43, 95%CI: 1.15-1.79; I2 = 73.3% comparing extreme intake categories). In a dose-response analysis, for red meat intake of 100 g/d, SRR was 1.84 (95%CI: 1.64-2.05). In contrast, in the meta-analysis of five prospective studies including a total of 2549 cases among 247746 participants, no significant association between red meat intake and EC risk (SRR = 0.97, 95%CI: 0.85-1.11; I2 = 4.9% comparing extreme intake categories) was observed.

CONCLUSION: Our meta-analysis found a significant linear association between red meat intake and EC risk based on case-control studies but this was not confirmed in prospective studies.

Keywords: Red meat, Endometrial cancer, Dose-response, Meta-analysis, Observational studies

Core tip: By conducting a dose-response meta-analysis, we found a significant linear association between red meat intake and endometrial cancer risk based on case-control studies. However this association was not confirmed in prospective studies. In our paper, we argue that those findings are attributable to methodological difference between retrospective case-control studies and prospective studies.