TY - JOUR
T1 - Lifestyle factors and colorectal cancer risk (1)
T2 - Systematic review and meta-analysis of associations with body mass index
AU - Harriss, D. J.
AU - Atkinson, G.
AU - George, K.
AU - Tim Cable, N.
AU - Reilly, T.
AU - Haboubi, N.
AU - Zwahlen, M.
AU - Egger, M.
AU - Renehan, A. G.
PY - 2009/7/1
Y1 - 2009/7/1
N2 - Objective: Excess body weight, defined by body mass index (BMI), may increase the risk of colorectal cancer. As a prerequisite to the determination of lifestyle attributable risks, we undertook a systematic review and meta-analysis of prospective observational studies to quantify colorectal cancer risk associated with increased BMI and explore for differences by gender, sub-site and study characteristics. Method: We searched MEDLINE and EMBASE (to December 2007), and other sources, selecting reports based on strict inclusion criteria. Random-effects meta-analyses and meta-regressions of study-specific incremental estimates were performed to determine the risk ratio (RR) and 95% confidence intervals (CIs) associated with a 5 kg/m2 increase in BMI. Results: We analysed 29 datasets from 28 articles, including 67361 incident cases. Higher BMI was associated with colon (RR 1.24, 95% CIs: 1.20-1.28) and rectal (1.09, 1.05-1.14) cancers in men, and with colon cancer (1.09, 1.04-1.12) in women. Associations were stronger in men than in women for colon (P <0.001) and rectal (P = 0.005) cancers. Associations were generally consistent across geographic populations. Study characteristics and adjustments accounted for only moderate variations of associations. Conclusions: Increasing BMI is associated with a modest increased risk of developing colon and rectal cancers, but this modest risk may translate to large attributable proportions in high-prevalence obese populations. Inter-gender differences point to potentially important mechanistic differences, which merit further research.
AB - Objective: Excess body weight, defined by body mass index (BMI), may increase the risk of colorectal cancer. As a prerequisite to the determination of lifestyle attributable risks, we undertook a systematic review and meta-analysis of prospective observational studies to quantify colorectal cancer risk associated with increased BMI and explore for differences by gender, sub-site and study characteristics. Method: We searched MEDLINE and EMBASE (to December 2007), and other sources, selecting reports based on strict inclusion criteria. Random-effects meta-analyses and meta-regressions of study-specific incremental estimates were performed to determine the risk ratio (RR) and 95% confidence intervals (CIs) associated with a 5 kg/m2 increase in BMI. Results: We analysed 29 datasets from 28 articles, including 67361 incident cases. Higher BMI was associated with colon (RR 1.24, 95% CIs: 1.20-1.28) and rectal (1.09, 1.05-1.14) cancers in men, and with colon cancer (1.09, 1.04-1.12) in women. Associations were stronger in men than in women for colon (P <0.001) and rectal (P = 0.005) cancers. Associations were generally consistent across geographic populations. Study characteristics and adjustments accounted for only moderate variations of associations. Conclusions: Increasing BMI is associated with a modest increased risk of developing colon and rectal cancers, but this modest risk may translate to large attributable proportions in high-prevalence obese populations. Inter-gender differences point to potentially important mechanistic differences, which merit further research.
UR - http://www.scopus.com/inward/record.url?scp=67749122332&partnerID=8YFLogxK
U2 - 10.1111/j.1463-1318.2009.01766.x
DO - 10.1111/j.1463-1318.2009.01766.x
M3 - Review article
C2 - 19207714
AN - SCOPUS:67749122332
SN - 1462-8910
VL - 11
SP - 547
EP - 563
JO - Colorectal Disease
JF - Colorectal Disease
IS - 6
ER -