The incidence and associated mortality rates of bladder cancer worldwide appear to be correlated with the rates of tobacco use, a recent international study has found, reports healthcare information provider CIMS Medica.
The CIMS article published in the last week, refers to an international study led by Hong Kong researchers into global trends in bladder cancer and their links to tobacco use and Gross Domestic Product Per Capita, published by the journal European Urology in September.
Researchers retrieved data on bladder cancer rates from three sources: the GLOBOCAN database, the Cancer Incidence in Five Countries, and the WHO mortality databases. Tobacco use was determined through information from the WHO Global Health Observatory.
In 2018, the researchers found 549,393 new cases of bladder cancer leading to 199,922 related deaths. These rates varied widely between sexes and across geographical regions.
In men, for instance, age-standardised rates of bladder cancer ranged from as low as 1.3 per 100,000 in middle Africa to a maximum of 26.5 per 100,00 in Southern Europe.
Sex-stratified bladder cancer mortality rates were 3.2 and 0.9 per 100,000 in men and women, respectively.
Notably, researchers detected a positive correlation between tobacco use and bladder cancer incidence (r, 0.20) and mortality (r, 0.38) in men. This was also true in women, but the effect of tobacco use on cancer incidence was stronger (r, 0.67), while its influence on associated mortality was weaker (r, 0.22).
This was confirmed through multivariable linear regression analysis of bladder cancer incidence (men: coefficient, 0.152, 95 percent confidence interval [CI], 0.017–0.286; p=0.027; women: coefficient, 0.116, 95 percent CI, 0.078–0.154; p<0.001). Mortality, on the other hand, was only significantly associated with tobacco use in men (coefficient, 0.067, 95 percent CI, 0.025–0.108; p=0.002).
“Tobacco use was significantly associated with both bladder cancer incidence and mortality. Hence, a global effort to promote smoking cessation is extremely important to reduce bladder cancer incidence and mortality in the long run,” the researchers said.
Global Trends of Bladder Cancer Incidence and Mortality, and Their Associations with Tobacco Use and Gross Domestic Product Per Capita
European Urology. Published on 21 September 2020
Jeremy Yuen-Chun Teoh , Junjie Huang , Wendy Yuet-Kiu Ko, Veeleah Lok, Peter Choi, Chi-Fai Ng, Shomik Sengupta, Hugh Mostafid, Ashish M Kamat, Peter C Black, Shahrokh Shariat, Marek Babjuk and Martin Chi-Sang Wong
The Chinese University of Hong Kong, Monash University, Royal Surrey County Hospital in the United Kingdom, University of Texas, University of British Columbia, Moscow State Medical University, The University of Jordan, Medical University of Vienna and Charles University in Czech Republic.
Bladder cancer is a major urological disease, with approximately 550,000 new cases diagnosed in 2018.
We examined gender-specific incidence and mortality patterns, and trends of bladder cancer from a global perspective. We further investigated their associations with tobacco use and gross domestic product (GDP) per capita.
Design, setting and participants
We retrieved data on the incidence and mortality of bladder cancer from the GLOBOCAN database, Cancer Incidence in Five Continents, and the WHO mortality database. Data on the rate of tobacco use were retrieved from the WHO Global Health Observatory. Data on GDP per capita was retrieved from the United Nations Human Development Report.
Outcome measurements and statistical analysis
We performed two sets of analyses. The first set of analysis is based on bladder cancer incidence and mortality data in 2018. The gender-specific age-standardised rates (ASRs) of incidence and mortality, and their correlations with the rate of tobacco use and GDP per capita were investigated.
A multivariable linear regression analysis was also performed. In the second set of analysis, we examined the 10-yr temporal trends of bladder cancer incidence and mortality by average annual percent change using joinpoint regression analysis.
A further exploratory analysis on GDP per capita in countries with decreasing trends of tobacco use was also performed.
Results and limitations
Wide variations in bladder cancer incidence and mortality were observed globally.
There were positive correlations between the rate of tobacco use and the ASRs of bladder cancer incidence (r=0.20) and mortality (r=0.38) in men, and between the rate of tobacco use and the ASRs of bladder cancer incidence (r=0.67) and mortality (r=0.22) in women.
There were positive correlations between GDP per capita, and the ASRs of bladder cancer incidence in men (r=0.48) and women (r=0.44). There was a weak positive correlation between GDP per capita and bladder cancer mortality in men (r=0.19), but no correlation with bladder cancer mortality in women (r=0.06).
Upon multivariable linear regression analysis, tobacco use was significantly associated with bladder cancer incidence and mortality in men, and bladder cancer incidence in women.
Regarding the 10-yr temporal trends of bladder cancer, Europe has an increasing incidence but decreasing mortality, and Asia has a decreasing incidence but increasing male mortality.
Among countries with decreasing trends of tobacco use, the mean GDP per capita was higher in countries with decreasing trends of bladder cancer mortality than in those with increasing trends of bladder cancer mortality. A major limitation of the study is that cancer incidence might be underdetected and under-reported in less developed nations.
There were observable trends of bladder cancer incidence and mortality globally. Tobacco use was significantly associated with both bladder cancer incidence and mortality. A certain level of economic capacity might be needed to further reduce bladder cancer mortality in countries with a decreasing trend of tobacco use.
There are different trends of bladder cancer incidence and mortality globally. Smoking is significantly associated with the incidence and mortality of bladder cancer. A higher financial capacity may be needed to further improve the disease outcomes.
CIMS Medica report – Tobacco linked to global trends in bladder cancer
European Urology article – Global Trends of Bladder Cancer Incidence and Mortality, and Their Associations with Tobacco Use and Gross Domestic Product Per Capita