Cancer – survival rates are up, but the number of cases is also rising
The 14 million new cancer cases worldwide recorded in 2012 will balloon to 24 million within two decades. Despite better ways of detecting and treating the disease today, ‘no real headway has been made’ in the fight against it
Even as cancer treatment improves and survival rates go up, so, too, does the number of people afflicted with the deadly disease, experts say.
The 14 million new cancer cases worldwide recorded in 2012 will balloon to 24 million within two decades, outstripping the increase in global population, according to the World Health Organisation.
All forms of cancer combined claimed 8.8 million lives in 2015, making it the second leading cause of death after heart disease.
“We know how to help avoid it, and to detect it. We’re getting better at treating it. But overall, we’re not making real headway in the fight against cancer,” says Christophe Leroux, head of communications for France’s League Against Cancer.
Several factors account for the disease’s growing prevalence. One is ageing populations, especially in developed nations and China, where a one-child-per-family policy in force for more than 30 years created a top-heavy age pyramid. Cancer risk increases with age.
There is also a long list of lifestyle habits linked to cancer, with tobacco consumption at the top. Other risk factors – all of them increasing – include eating poorly, lack of exercise, drinking alcohol, and obesity.
Cancer-causing infections such as hepatitis and the human papilloma virus (HPV) account for a quarter of cancer cases, mostly in low- and middle-income countries.
Another risk is exposure to carcinogenic industrial pollutants, including asbestos, organic pollutants such as dioxins, heavy metals and small air particles that lodge in the lungs.
Despite the growing challenges, five-year survival rates for most cancers have improved – sometimes significantly – since 2000, according to a study published last week in medical journal The Lancet that reviewed 37.5 million cancer cases between 2000 and 2014.
But large disparities between societies remain, depending on level of development and differences in health case systems.
For children with brain tumours, for example, five-year survival has improved across the board from 54 per cent between 2000 and 2004, to more than 60 per cent for 2010 to 2014. In the United States, Denmark, Sweden and Slovakia, the survival rate progressed to 80 per cent or better.
In Mexico and Brazil, however, less than 40 per cent of children diagnosed with brain tumours survived in the 2010 to 2014 period.
Breast cancer rates also improved across the board, even as disparities remained. Five-year survival rates for 2010 to 2014 in the US and Australia were 90 per cent. In western and eastern Europe, the rate improved to 85 and 71 per cent, respectively.
“If we want fewer deaths from cancer, there are two ways: first, better prevention, and second, improving outcomes,” says co-author Michel Coleman, an epidemiologist and researcher at the London School of Hygiene and Tropical Medicine.
Cancer is also a costly disease, both for health care systems and society at large. Globally, the total annual economic cost of cancer exceeds US$1 trillion (HK$7.8 trillion), according to the WHO.
Lost productivity due to premature cancer deaths in five emerging economies – China, India, Brazil, South Africa and Russia – was more than US$46 billion in 2012, according a study released last week by the UN’s International Agency for Research on Cancer.
“It seems plausible that the global cost of cancer treatment and care in 2017 must already be substantially higher than US$300 billion,” the authors of the Lancet study conclude.
Inevitably, less money also means higher death rates.
“A lack of access to treatment is leading to premature deaths which could have otherwise been prevented,” says Sanchia Aranda, head of Cancer Council Australia.
“Low- and middle-income countries face the brunt as millions of people die prematurely from cancer every year as a result of inequities in access to diagnosis.”