Association between anthropometric characteristics and bladder cancer
risk: a systematic review and meta-analysis of longitudinal cohort
studies
Abstract
Background/ Aims Anthropometric characteristics, namely
overweight/obesity, height and waist circumference have been associated
with various cancer types. The aim of this systematic review and
meta-analysis is to evaluate the potential associations between
anthropometric characteristics and bladder cancer risk, synthesizing
longitudinal cohort studies. Methods Literature search across MEDLINE,
EMBASE, Scopus, Google Scholar and Cochrane Central was performed up to
December 31, 2019 and data abstraction was performed independently by
two authors. Random-effects (DerSimonian-Laird) models were used to
estimate pooled relative risks (RR) and 95% confidence intervals
(95%CI); subgroup analyses were performed geographical region, mean
age, publication year, length of follow-up, sample size, method of BMI
estimation and adjustment for smoking. Results A total of 27 studies
were included (88,593 bladder cancer cases in a total cohort of
49,647,098 subjects). Increased bladder cancer risk was noted in
overweight men (pooled RR=1.12, 95%CI: 1.04-1.21) but not in overweight
women. Both obese men (pooled RR=1.14, 95%CI: 1.06-1.22) and women
(pooled RR=1.19, 95%CI: 1.02-1.38) showed increased risk.
Interestingly, height increase per 5 cm did not seem to affect risk of
bladder cancer in men (pooled RR=1.03, 95%CI: 0.99- 1.06) and women
(pooled RR=1.02, 95%CI: 0.97-1.06). Larger waist circumference was
associated with bladder cancer risk in men (pooled RR=1.18, 95%CI:
1.09-1.26) but not women. Conclusion In conclusion, bladder cancer risk
seems to be related with obesity overall and central obesity in men. In
contrast to other cancer types, height does not seem to affect risk, but
more studies are needed to extract safe conclusions.