A new study published in The Lancet found that 44.4% of cancer deaths in 2019 were attributable to avoidable risk factors, Joseph Choi reports for The Hill.

Study details and key findings

For the study, researchers analyzed data from the 2019 Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). They used the GBD risk-assessment framework to estimate behavioral, environmental, occupational, and metabolic risk factors for cancer. In total, they included 82 risk-outcome pairs based on the World Cancer Research Fund criteria.

In 2019, those risk factors accounted for 4.45 million deaths worldwide and 105 million disability-adjusted life-years (DALYs)—the number of years lost to not living at full health or with a disability. They represented 44.4% of all cancer deaths and 42% of all DALYs. 

During that period, there were nearly 3 million risk-attributable cancer deaths in men and more than 1.5 million risk-attributable cancer deaths in women.

The top 10 global leading risk factors for cancer deaths and DALYs include:

1. Smoking
2. Alcohol use
3. High body mass index
4. Unsafe sex
5. High fasting plasma glucose
6. Ambient particulate matter pollution
7. Occupational exposure to asbestos
8. Diet low in whole grains
9. Diet low in milk
10. Second-hand smoke

However, the burden of risk-attributable cancer differed by world region and Socio-demographic Index (SDI). For instance, in low SDI locations, smoking, unsafe sex, and alcohol use were the three leading risk factors. In comparison, high SDI locations shared the top three global risk factors.

According to the study, global risk-attributable cancer deaths increased by 20.4% from 2010 to 2019, and DALYs increased by 16.8%.

Commentary

The researchers suggested that governments could mitigate risk-attributable cancer deaths by creating and supporting environments that will minimize exposure to cancer risk factors.

"Although some cancer cases are not preventable, governments can work on a population level to support an environment that minimises exposure to known cancer risk factors," researchers said.

"Primary prevention, or the prevention of a cancer developing, is a particularly cost-effective strategy, although it must be paired with more comprehensive efforts to address cancer burden, including secondary prevention initiatives, such as screening programmes, and ensuring effective capacity to diagnose and treat those with cancer," they added.

According to the researchers, governments have already made "substantial progress" in reducing exposure to tobacco. In particular, they highlighted interventions like taxation, regulations, and smoke-free policies that have been implemented in by many governments around the world.

"Behavioural risk factors are strongly influenced by the environment in which people live and individuals with cancer should not be blamed for their disease," the researchers said. (Choi, The Hill, 8/19; GBD 2019 Cancer Risk Factors Collaborators, The Lancet, 8/20)