The researchers suggest people in countries without universal healthcare coverage rely on the health insurance provided by their employers, and without employment, they may be diagnosed late, and face poor or delayed treatment.
For countries in the Organisation for Economic Development (OECD), they estimate the crisis is linked to over 260,000 additional cancer deaths, including 160,000 in the European Union.
The researchers, from institutions in the United States and the United Kingdom, discuss their analysis in a paper published in The Lancet.
In their paper, they explain how the crisis that hit economies around the world in 2008-2010 was accompanied by a substantial rise in unemployment and caused many countries to cut their spending on public sector healthcare.
Several studies have shown that these changes are linked to negative effects on public health - for instance, increases in suicide and cardiovascular diseases.
Lead author Dr. Mahiben Maruthappu, of the Faculty of Medicine at Imperial College London in the U.K., explains as cancer is a leading cause of death worldwide, it is very important to look at the effect economic changes may have on cancer survival. He notes:
"We found that increased unemployment was associated with increased cancer mortality, but that universal health coverage protected against these effects. This was especially the case for treatable cancers including breast, prostate and colorectal cancer."
He and his colleagues also found that public healthcare expenditure was tightly linked with cancer deaths - suggesting cuts in healthcare may cost lives.
"If health systems experience funding constraints," says Dr. Maruthappu, "this must be matched by efficiency improvements to ensure patients are offered the same level of care, regardless of economic environment or employment status."
Unemployment effect disappears with healthcare
The researchers obtained economic data from the World Bank and figures on cancer deaths from the World Health Organization (WHO) Mortality Database to analyze links between unemployment, public healthcare spending, and cancer deaths. The overall data spanned 2 decades - from 1990-2010 - and covered 2 billion people in over 70 countries.
- Globally, there were 8.2 million cancer-related deaths in 2012
- The number of new cancer cases per year is expected to rise from 14 million in 2012 to 22 million within the next 2 decades
- Tobacco use, alcohol use, unhealthy diet, and lack of physical activity are the main risk factors worldwide.
The analysis included deaths from prostate cancer, breast cancer, colorectal cancer, and lung cancer. Cancers with survival rates exceeding 50 percent were classed as treatable, while those with survival rates under 10 percent were classed as untreatable.
In analyses looking at deaths from all cancers, the researchers set strict inclusion criteria to ensure only high-quality data was used. For example, they excluded countries with less than 90 percent civil registration coverage of cause of death for the study period.
They deemed countries to have universal healthcare coverage if they met certain criteria. These included, for example, legislation mandating universal healthcare coverage, some form of health insurance being available to 90 percent of the population, and over 90 percent of the population having access to skilled birth attendance.
The results show that increases in unemployment were tied to increases in deaths to all types of cancer, but this link disappeared when the figures were adjusted to take universal healthcare into account.
The authors note that although "treatable cancer mortality was significantly linked with unemployment," they could find no such significance for untreatable cancers. They suggest this finding highlights the importance of ensuring access to healthcare.
Co-author Professor Rifat Atun, of Harvard University in Cambridge, MA, says people in countries without universal healthcare coverage rely on the health insurance provided by their employers, and suggests:
"Without employment, patients may be diagnosed late, and face poor or delayed treatment."
Additional 260,000 cancer deaths in OECD
The study also shows that cancer deaths rose as public sector health spend fell.
The team then used the findings to produce estimates for countries in the OECD, some of which were not covered by the World Bank and WHO data sets.
The estimates suggest the 2008-2010 global economic crisis was linked to an extra 263,221 cancer deaths in the OECD, of which 169,129 were in the European Union.
The OECD currently comprises 34 members and includes many of the world's most advanced countries but also emerging countries like Mexico, Chile, and Turkey.
The authors point out their findings can only show a link between cancer deaths, unemployment, and public sector spending - they cannot prove cause and effect. However, they note that because their analyses show one follows the other - trends in cancer deaths shadowed changes in unemployment - this implies support for a causal link.
In an accompanying article, Dr. Graham A Colditz, of the Washington University School of Medicine, St Louis, MO, and Dr. Karen M Emmons, of the Kaiser Foundation Research Institute, Oakland, CA, comment that the findings support the idea that making universal health coverage more widespread would likely further reduce deaths to cancer.
They suggest that the U.S. - which currently does not have universal healthcare coverage - might "find the promise of improving treatments difficult to achieve without first providing coverage to those affected by cancer."
Not only would universal health coverage - specifically for all cancer patients - meet the Institute of Medicine recommendation for eliminating disparities in access, it would also "generate a great return on investment," they note.
"Universal health coverage is a key UN Development Programme Sustainable Development Goal (SDG 3) and is described as the single most powerful concept that public health has to offer."
Dr. Graham A. Colditz and Dr. Karen M. Emmons