In an analysis from the Global Burden of Disease Study 2019 reported in The Lancet, researchers from the GBD 2019 Cancer Risk Factors Collaborators found that cancers attributable to behavioral, environmental/occupational, and metabolic risk factors accounted for 44% of all cancer deaths globally in 2019. Deaths due to these risk factors increased by 20% compared with 2010.
Study Details
The analysis included 82 risk-outcome pairings, comprising 23 cancer types and 34 risk factors. Behavioral, environmental/occupational, and metabolic risk factors included tobacco use, alcohol use, unsafe sex, dietary risks, low physical activity, drug use, air pollution, occupational exposure to carcinogens, high body mass index (BMI), and high fasting plasma glucose. Risk-attributable cancer-related disability-adjusted life-years (DALYs) were calculated as the sum of years of life lost and years of life lived with disability due to cancer.
Key Findings
In 2019, the risk factors included in the analysis accounted globally for 4.45 million (95% uncertainty interval [UI] = 4.01–4.94 million) deaths and 105 million (95% UI = 95.0–116 million) cancer DALYs for both sexes combined. This burden accounted for 44.4% (95% UI = 41.3%–48.4%) of all cancer deaths and 42.0% (95% UI = 39.1%–45.6%) of all cancer DALYs.
In males, there were 2.88 million (95% UI = 2.60–3.18 million) risk-attributable cancer deaths, accounting for 50.6% (95% UI = 47.8%–54.1%) of all cancer deaths, and 67.5 million (95% UI = 60.8–75.1 million) cancer DALYs, accounting for 48.0% (95% UI = 45.3%–51.5%) of all cancer DALYs. In females, there were 1.58 million (95% UI = 1.36–1.84 million) risk-attributable cancer deaths, accounting for 36.3% (95% UI = 32.5%–41.3%) of all cancer deaths and 37.6 million (95% UI = 32.8–43.1 million) cancer DALYs, accounting for 34.3% (95% UI = 30.9%-38.7%) of all cancer DALYs. Globally, the leading risk factors for risk-attributable cancer deaths and DALYs for both sexes combined were smoking, alcohol use, and high BMI.
Risk-attributable cancer deaths for both sexes combined occurred disproportionately more frequently in high sociodemographic index (SDI) countries; these countries accounted for 26.5% (95% UI = 24.9%–28.1%) of risk-attributable cancer deaths, despite constituting 13.1% (95% UI = 12.5%–13.8%) of the global population. The leading risk factors for risk-attributable cancer death and DALYs were smoking, alcohol use, and high BMI in high-SDI countries, and smoking, unsafe sex, and alcohol use in low-SDI countries.
From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (95% UI = 12.6%–28.4%) and DALYs by 16.8% (95% UI = 8.8%–25.0%). The greatest percentage increase was due to metabolic risks, with attributable deaths increasing by 34.7% (95% UI = 27.9%–42.8%) and DALYs by 33.3% (95% UI = 25.8%–42.0%). Behavioral risk-attributable deaths and DALYs increased by 17.9% (95% UI = 10.4%–26.0%) and 14.4% (95% UI = 6.5%–22.5%), respectively.
The investigators concluded, “The leading risk factors contributing to global cancer burden in 2019 were behavioral, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden.”
Christopher J.L. Murray, DPhil, of the Institute for Health Metrics and Evaluation, University of Washington, Seattle, is the corresponding author for The Lancet article.
Disclosure: The study was funded by the Bill & Melinda Gates Foundation. For full disclosures of the study authors, visit thelancet.com.
