Global Changes in Bladder Cancer Mortality in the Elderly - Beyond the Abstract

Our recent paper, published in Cancer Epidemiology, explores how global bladder cancer mortality has changed in the elderly. We analysed the World Health Organisation’s GLOBOCAN database which provides mortality data from many countries around the world.

The global aging population was adjusted by using age-standardisation. Mortality has been decreasing throughout the countries we studied. Men aged ≥75 have had an Age-Standardised Mortality Rate (ASMR) annual change of -11.2% compared to -39.4% in men aged <75. Women aged ≥75 saw an annual decrease in ASMR of -16.4% compared to -26.4% in women aged <75.

Global bladder cancer incidence has been decreasing in people aged <75 and remains static in those aged ≥75. Once changes in bladder cancer incidence had been factored in, there are only modest improvements in bladder cancer mortality in all ages (mortality: incidence ratio -0.83% annual change in those aged 60-74) with the smallest improvements in those aged ≥75 (-0.36%).

The GLOBOCAN database is biased towards More Economically Developed Countries (MEDCs) as these countries tend to maintain and submit data from high quality registries. Concerningly, bladder cancer mortality is increasing for people aged ≥75 in countries with a Human Development Index (HDI) <0.87. A lower HDI score correlates to a lower standard of living, as measured by life expectancy at birth, mean years of schooling and gross domestic product per capita. Only 35 of 191 countries had a HDI >0.87 in the latest 2022 UN Human Development Report.

The causes for the smaller improvement in elderly mortality may include the elderly having greater co-morbidities and less access to bladder cancer treatments such as cystectomy and BCG, as reported in numerous retrospective studies published in the past decade.

We are currently analysing the South Australian Cancer Registry to explore whether histological change over time and access to healthcare affect bladder cancer survival in addition to analysing how survival is changing amongst different age groups.

We have previously reported decreasing survival of bladder cancer despite being in an era of BCG immunotherapy, promising neoadjuvant chemotherapy outcomes, and advances in multidisciplinary care. Data from the South Australian cancer registry reveal that the mean age of bladder cancer diagnosis has increased from 68 in 1977 to 76 in 2019, which reflects improvements in delaying the onset, possibly resulting from reduced exposure to carcinogens.

The seemingly counterintuitive situation of improving mortality and deteriorating survival may be explained by fewer people developing bladder cancer and the increasing age at diagnosis. Mortality, the total number of deaths per 100,000 people, differs from survival in that mortality is affected by incidence and includes all bladder cancer deaths regardless of when they are diagnosed. Survival is only measured when a diagnosis is made and is not affected by incidence. More is being done to confirm the causes of survival changes.

For all clinicians treating bladder cancer, it is worth bearing in mind that despite more than half of our patients being over 75 when they are diagnosed, the elderly are offered fewer treatment options than younger patients and face similarly poor outcomes to patients diagnosed 40 years ago.

Written by:

  • Jake Tempo, Department of Urology, Austin Health, Melbourne, Australia
  • Joseph Ischia, Department of Urology, Austin Health, Melbourne, Australia
  • Michael O’Callaghan, Discipline of Medicine, University of Adelaide, Adelaide, Australia
Read the Abstract