A new global analysis highlights the substantial burden of premature deaths from cancer around the world – a burden that could potentially be averted through prevention, early detection, and timely treatment.
According to the analysis, in 2020, over half of all cancer deaths – 5.28 million of 9.96 million – occurred prematurely (before age 70), leading to a loss of roughly 183 million life-years from the disease worldwide.
More than two-thirds of premature cancer-related deaths – 3.6 million, or 68% – were potentially preventable through lifestyle changes or early detection efforts, such as cancer screening, dietary changes, or smoking cessation, and about one-third – 1.65 million, or 31% – may have been treatable.
But two biostatisticians not involved in the study who took a deep dive into it urged caution in interpreting the data.
Nilanjan Chatterjee, PhD, Bloomberg Distinguished Professor, Bloomberg School of Public Health at Johns Hopkins University, Baltimore, said the study does a “great job in bringing a lot of diverse data together to show there is very high potential for preventing premature deaths due to cancer worldwide.”
However, for a variety of reasons, Dr. Chatterjee explained, one should not “overinterpret” the high percentage of potentially preventable cancer deaths.
Gideon Meyerowitz-Katz, PhD, an epidemiologist at the University of Wollongong, in Australia, agreed.
“It’s likely many cancer deaths are, in theory, preventable, but the numbers around just how many are necessarily vague,” said Dr. Meyerowitz-Katz. “Also, ‘in theory preventable’ doesn’t necessarily mean that we can actually do it in practice.”
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The study, led by researchers from the World Health Organization’s International Agency for Research on Cancer and partners, provides estimates of premature deaths from 36 cancers across 185 countries.
The findings, published in The Lancet Global Health along with a new Lancet Commission report – “Women, Power, and Cancer” also highlighted the “underrecognized” cancer burden among women around the world.
Cancer ranks in the top three causes of premature mortality among women in almost all countries worldwide, but it is often “deprioritized,” the Lancet Commission report explained.
Of the nearly 5.3 million premature cancer deaths in 2020, 2.9 million occurred in men, and 2.3 million occurred in women, the investigators found. Of the premature deaths among women, 1.5 million could have potentially been avoided through prevention or detection efforts, while the remaining 800,000 might have been averted “if all women everywhere could access optimal cancer care,” the authors said.
Lung cancer was the leading contributor to preventable premature years of life lost in countries that have medium to very high scores on the Human Development Index (HDI), whereas cervical cancer was the leading contributor in low-HDI countries. HDI rankings are based on life expectancy, education, and gross national income.
Among women, as many as 72% of cancer death were premature in low-HDI countries, vs 36% in very high-HDI countries.
Overall, across all four tiers of HDI, colorectal and breast cancers represented the major treatable cancers.
Reducing exposure to four main risk factors – tobacco smoking, alcohol consumption, high body weight, and infections – would go a long way toward reducing potentially preventable premature cancer-related deaths, the authors said.
“Globally, there are marked inequalities between countries in reaching the target of reducing premature mortality from noncommunicable diseases, including cancer,” author Isabelle Soerjomataram, MD, PhD, deputy head of cancer surveillance at the International Agency for Research on Cancer, said in a press release.
“Greater investments in cancer prevention programs can reduce the prevalence of key risk factors for cancer, and increased coverage of vaccination alongside early diagnosis and screening linked to timely treatment can and must address the current cancer inequalities that are seen worldwide,” she added.