Height and body fatness and colorectal cancer risk: an update of the WCRF–AICR systematic review of published prospective studies

Abstract

PurposeThere is no published dose–response meta-analysis on the association between height and colorectal cancer risk (CRC) by sex and anatomical sub-site. We conducted a meta-analysis of prospective studies on the association between height and CRC risk with subgroup analysis and updated evidence on the association between body fatness and CRC risk.MethodsPubMed and several other databases were searched up to November 2016. A random effects model was used to calculate dose–response summary relative risks (RR’s).Results47 studies were included in the meta-analyses including 50,936 cases among 7,393,510 participants. The findings support the existing evidence regarding a positive association of height, general and abdominal body fatness and CRC risk. The summary RR were 1.04 [95% (CI)1.02–1.05, I² = 91%] per 5 cm increase in height, 1.02 [95% (CI)1.01–1.02, I² = 0%] per 5 kg increase in weight, 1.06 [95% (CI)1.04–1.07, I² = 83%] per 5 kg/m2 increase in BMI, 1.02 [95% (CI)1.02–1.03, I² = 4%] per 10 cm increase in waist circumference, 1.03 [95% (CI)1.01–1.05, I² = 16%] per 0.1 unit increase in waist to hip ratio. The significant association for height and CRC risk was similar in men and women. The significant association for BMI and CRC risk was stronger in men than in women.ConclusionThe positive association between height and risk of CRC suggests that life factors during childhood and early adulthood might play a role in CRC aetiology. Higher general and abdominal body fatness during adulthood are risk factors of CRC and these associations are stronger in men than in women.Electronic supplementary materialThe online version of this article (doi:10.1007/s00394-017-1557-1) contains supplementary material, which is available to authorized users.

Adiposity and risks of colorectal and small intestine cancer in Chinese adults: a prospective study of 0.5 million people

“…A recent meta-analysis of 38 prospective cohort studies (> 71,000 cases) reported a 6% higher risk of CRC per 5 kg/ m 2 higher BMI, 2 with somewhat stronger associations in men than women and for colon than rectal cancer. 2 Despite the much lower mean BMI in China than in North America or Europe, 6 For WC and WHR, the risk estimates reported in the metaanalysis were somewhat weaker than our estimates. 2 Moreover, unlike in the present study, they differed little by sex and by anatomical site.…”

“…2 Despite the much lower mean BMI in China than in North America or Europe, 6 For WC and WHR, the risk estimates reported in the metaanalysis were somewhat weaker than our estimates. 2 Moreover, unlike in the present study, they differed little by sex and by anatomical site. 2 Of all included studies, four studies showed that WC or WHR was more important than BMI in predicting the risk of CRC, while the converse was true for the other two studies.…”

“…2 Of all included studies, four studies showed that WC or WHR was more important than BMI in predicting the risk of CRC, while the converse was true for the other two studies. 2 Our study showed that the association of BMI with CRC risk attenuated when further adjusting for WC, while the association of WC persisted when further controlling for BMI.…”

“…1 Uncertainty remains, however, as to whether the association differs by sex or by its anatomical site. Moreover, the evidence is rather limited in the East Asian population, 2 particularly China, where the mean levels of adiposity in the adult population are still much lower than those in the Western population. Despite the low incidence, small intestine cancer (SIC) may arise from the same origin as that of CRC, and therefore may share similar risk factors.…”

Dietary consumption of antioxidant vitamins and subsequent lung cancer risk: The Japan Public Health Center‐based prospective study

“…Although the oncogenic mechanisms of the harmful effects of antioxidants have not been completely elucidated, it has been suggested that a high-dose intake of certain antioxidants may act as conditional pro-oxidants under high oxidative stress and exposure to lung irritants such as tobacco smoking and asbestos; and that the activity of an antioxidant is dependent on its redox potential in connection with other pro-and anti-oxidants in its microenvironment. 29,33 In a recent systematic review of blood concentrations of carotenoids and retinol, higher blood concentrations of b-carotene and retinol were inversely associated with lung cancer risk in men and not in women, 34 which illustrates the need to explore the difference between dietary intake and blood concentration. Furthermore, there are accumulating epidemiologic evidence showing gender differences in susceptibility to lung cancer.…”