RT Journal Article
SR Electronic
T1 Obesity and Risk of Colorectal Cancer: A Meta-analysis of 31 Studies with 70,000 Events
JF Cancer Epidemiology Biomarkers & Prevention
JO Cancer Epidemiol Biomarkers Prev
FD American Association for Cancer Research
SP 2533
OP 2547
DO 10.1158/1055-9965.EPI-07-0708
VO 16
IS 12
A1 Moghaddam, Alireza Ansary
A1 Woodward, Mark
A1 Huxley, Rachel
YR 2007
UL http://cebp.aacrjournals.org/content/16/12/2533.abstract
AB Background: Colorectal cancer is the second most common cause of death and illness in developed countries. Previous reviews have suggested that obesity may be associated with 30% to 60% greater risk of colorectal cancer, but little consideration was given to the possible effect of publication bias on the reported association. Methods: Relevant studies were identified through EMBASE and MEDLINE. Studies were included if they had published quantitative estimates of the association between general obesity [defined here as body mass index (BMI) ≥30 kg/m2] and central obesity (measured using waist circumference) and colorectal cancer. Random-effects meta-analyses were done, involving 70,000 cases of incident colorectal cancer from 31 studies, of which 23 were cohort studies and 8 were case-control studies. Results: After pooling and correcting for publication bias, the estimated relative risk of colorectal cancer was 1.19 [95% confidence interval (95% CI), 1.11-1.29], comparing obese (BMI ≥30 kg/m2) with normal weight (BMI <25 kg/m2) people; and 1.45 (95% CI, 1.31-1.61), comparing those with the highest, to the lowest, level of central obesity. After correcting for publication bias, the risk of colorectal cancer was 1.41 (95% CI, 1.30-1.54) in men compared with 1.08 (95% CI, 0.98-1.18) for women (Pheterogeneity <0.001). There was evidence of a dose-response relationship between BMI and colorectal cancer: for a 2 kg/m2 increase in BMI, the risk of colorectal cancer increased by 7% (4-10%). For a 2-cm increase in waist circumference, the risk increased by 4% (2-5%). Conclusions: Obesity has a direct and independent relationship with colorectal cancer, although the strength of the association with general obesity is smaller than previously reported. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2533–47)