Article type
Year
Abstract
Background: cancer is a major health problem in high-income and low-to-middle-income countries, and is the second leading cause of death in the world. Several meta-analyses have investigated the effect of body-mass index (BMI) increase on the incidence and mortality of cancer, but there are considerable differences in conclusions of the associations between BMI and different urinary cancers.
Objectives: this overview aimed to assess the methodological and reporting quality of systematic reviews that evaluated the assocition between BMI increase and urinary cancer risks.
Methods: we searched PubMed, Embase and the Cochrane Library to identify relevant meta-analyses and systematic reviews. We assessed methodological quality using the AMSTAR checklist, and reporting quality using the PRISMA checklist. We estimated the association between BMI and urinary cancers by computing the pooled risk ratio (RR) and its 95% confidence interval (CI). In this meta-analysis, we deemed hazard ratios (HRs) and odds ratios (ORs) equivalent to RRs. We assessed heterogeneity between studies with the I2 statistic as a measure of the proportion of total variation in estimates that is due to heterogeneity. We also conducted indirect comparisons using the combined outcomes.
Results: the median (range) AMSTAR scores were 7.0 (4.0 to 10.0); the median (range) PRISMA-DTA scores were 22.0 (15.5 to 26.0). The association between obesity and incidence of kidney cancer was significantly stronger than bladder cancer and prostate cancer. The association between overweight and incidence of kidney cancer was also stronger than bladder cancer and prostate cancer. For dose-analysis, the RR (per 5 kg/m2 increase) of BMI was observed to have stronger association with kidney cancer than bladder cancer and prostate cancer. Compared to mortality of bladder cancer, kidney cancer and prostate cancer were more strongly associated with BMI increase (per 5 kg/m2 increase). Gender, population, age, and hypertension are significant factors affecting the association between obesity and cancer incidence (P < 0.05).
Conclusions: based on the current evidence, overweight and obesity are strong risk factors for the incidence and mortality of urinary cancers. Furthermore, we found that this effect varies between different urinary cancers. According to our analyses, gender, population, age, and hypertension are also significant factors affecting the association between obesity and cancer incidence. Further study might be needed to determine the patient or healthcare consumer involvement.
Objectives: this overview aimed to assess the methodological and reporting quality of systematic reviews that evaluated the assocition between BMI increase and urinary cancer risks.
Methods: we searched PubMed, Embase and the Cochrane Library to identify relevant meta-analyses and systematic reviews. We assessed methodological quality using the AMSTAR checklist, and reporting quality using the PRISMA checklist. We estimated the association between BMI and urinary cancers by computing the pooled risk ratio (RR) and its 95% confidence interval (CI). In this meta-analysis, we deemed hazard ratios (HRs) and odds ratios (ORs) equivalent to RRs. We assessed heterogeneity between studies with the I2 statistic as a measure of the proportion of total variation in estimates that is due to heterogeneity. We also conducted indirect comparisons using the combined outcomes.
Results: the median (range) AMSTAR scores were 7.0 (4.0 to 10.0); the median (range) PRISMA-DTA scores were 22.0 (15.5 to 26.0). The association between obesity and incidence of kidney cancer was significantly stronger than bladder cancer and prostate cancer. The association between overweight and incidence of kidney cancer was also stronger than bladder cancer and prostate cancer. For dose-analysis, the RR (per 5 kg/m2 increase) of BMI was observed to have stronger association with kidney cancer than bladder cancer and prostate cancer. Compared to mortality of bladder cancer, kidney cancer and prostate cancer were more strongly associated with BMI increase (per 5 kg/m2 increase). Gender, population, age, and hypertension are significant factors affecting the association between obesity and cancer incidence (P < 0.05).
Conclusions: based on the current evidence, overweight and obesity are strong risk factors for the incidence and mortality of urinary cancers. Furthermore, we found that this effect varies between different urinary cancers. According to our analyses, gender, population, age, and hypertension are also significant factors affecting the association between obesity and cancer incidence. Further study might be needed to determine the patient or healthcare consumer involvement.
PDF