Nearly half of all cancer deaths could be prevented, study says

Smoking was listed as the leading cancer risk factor worldwide, but experts stressed that other ‘substantial contributors to cancer burden’ vary across the globe. 

The researchers from the University of Washington’s School of Medicine found that these combined factors contributed to nearly 4.45 cancer deaths a year – the equivalent of 44 percent of all such deaths. 

In total, just over half (50.6 percent) of all male cancer deaths in 2019 were due to risk factors, compared to around a third of all female cancer deaths (36.3 percent). 

While cancer is a leading cause of death - second after heart disease worldwide - this is the first study to examine a multitude of factors on a global level, according to its authors.

For the study, which was funded by the Bill & Melinda Gates Foundation, the team used data from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2019 study to estimate ‘cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors’. 

The researchers said their findings highlighted that a ‘substantial proportion of cancer burden globally has potential for prevention through interventions aimed at reducing exposure to known cancer risk factors’, but that also ‘a large proportion of cancer burden might not be avoidable through control of the risk factors currently estimated’. 

“Thus, cancer risk reduction efforts must be coupled with comprehensive cancer control strategies that include efforts to support early diagnosis and effective treatment,” they wrote. 

“Most attributable cancer DALYs [disability-adjusted life years] were accounted for by behavioural risk factors, such as tobacco use, alcohol use, unsafe sex, and dietary risks, suggesting a need for concerted efforts to address behavioural risk factors to effectively reduce cancer burden globally.”