Susanna C Larsson1, Alicja Wolk. 1. Division of Nutritional Epidemiology, National Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. susanna.larsson@ki.se
Abstract
BACKGROUND: Whereas obesity has been associated with an increased risk of colon cancer in men, a weak or no association has been observed in women. Results for rectal cancer have also been inconsistent. OBJECTIVE: The objective was to perform a meta-analysis to summarize the available evidence from prospective studies on the associations of overall and abdominal obesity with the risk of colon and rectal cancer. DESIGN: We searched MEDLINE (1966-April 2007) and the references of the retrieved articles. Study-specific relative risks (RRs) were pooled by using a random-effects model. RESULTS: Thirty prospective studies were included in the meta-analysis of body mass index (BMI; in kg/m(2)). Overall, a 5-unit increase in BMI was related to an increased risk of colon cancer in both men (RR: 1.30; 95% CI: 1.25, 1.35) and women (RR: 1.12; 95% CI: 1.07, 1.18), but the association was stronger in men (P < 0.001). BMI was positively associated with rectal cancer in men (RR: 1.12; 95% CI: 1.09, 1.16) but not in women (RR: 1.03; 95% CI: 0.99, 1.08). The difference in RRs between cancer sites was statistically significant (P < 0.001 in men and P = 0.04 in women). Colon cancer risk increased with increasing waist circumference (per 10-cm increase) in both men (RR: 1.33; 95% CI: 1.19, 1.49) and women (RR: 1.16; 95% CI: 1.09, 1.23) and with increasing waist-hip ratio (per 0.1-unit increase) in both men (RR: 1.43; 95% CI: 1.19, 1.71) and women (RR: 1.20; 95% CI: 1.08, 1.33). CONCLUSIONS: The association between obesity and colon and rectal cancer risk varies by sex and cancer site.
BACKGROUND: Whereas obesity has been associated with an increased risk of colon cancer in men, a weak or no association has been observed in women. Results for rectal cancer have also been inconsistent. OBJECTIVE: The objective was to perform a meta-analysis to summarize the available evidence from prospective studies on the associations of overall and abdominal obesity with the risk of colon and rectal cancer. DESIGN: We searched MEDLINE (1966-April 2007) and the references of the retrieved articles. Study-specific relative risks (RRs) were pooled by using a random-effects model. RESULTS: Thirty prospective studies were included in the meta-analysis of body mass index (BMI; in kg/m(2)). Overall, a 5-unit increase in BMI was related to an increased risk of colon cancer in both men (RR: 1.30; 95% CI: 1.25, 1.35) and women (RR: 1.12; 95% CI: 1.07, 1.18), but the association was stronger in men (P < 0.001). BMI was positively associated with rectal cancer in men (RR: 1.12; 95% CI: 1.09, 1.16) but not in women (RR: 1.03; 95% CI: 0.99, 1.08). The difference in RRs between cancer sites was statistically significant (P < 0.001 in men and P = 0.04 in women). Colon cancer risk increased with increasing waist circumference (per 10-cm increase) in both men (RR: 1.33; 95% CI: 1.19, 1.49) and women (RR: 1.16; 95% CI: 1.09, 1.23) and with increasing waist-hip ratio (per 0.1-unit increase) in both men (RR: 1.43; 95% CI: 1.19, 1.71) and women (RR: 1.20; 95% CI: 1.08, 1.33). CONCLUSIONS: The association between obesity and colon and rectal cancer risk varies by sex and cancer site.
Authors: Aaron S Rickles; James C Iannuzzi; Oleg Mironov; Andrew-Paul Deeb; Abhiram Sharma; Fergal J Fleming; John R T Monson Journal: J Gastrointest Surg Date: 2012-10-23 Impact factor: 3.452
Authors: Elizabeth T Jacobs; Dennis J Ahnen; Erin L Ashbeck; John A Baron; E Robert Greenberg; Peter Lance; David A Lieberman; Gail McKeown-Eyssen; Arthur Schatzkin; Patricia A Thompson; María Elena Martínez Journal: Am J Epidemiol Date: 2009-01-15 Impact factor: 4.897
Authors: Jenny N Poynter; Maki Inoue-Choi; Julie A Ross; David R Jacobs; Kimberly Robien Journal: Cancer Epidemiol Biomarkers Prev Date: 2013-02-19 Impact factor: 4.254