Nearly half of cancer deaths are preventable

A first-of-its-kind global report concludes that nearly half of cancer deaths worldwide are linked to preventable risk factors, which are largely behavioral.

The authors found that the most contributing factors were smoking, alcohol, and a high body mass index (BMI). The highest increases in cancer deaths over the past 10 years are associated with metabolic factors, such as obesity, particularly in low-income countries, the researchers point out.

“Tobacco use continues to be the leading risk factor for cancer worldwide,” note the authors. The main cancers implicated in risk-attributable deaths worldwide in 2019 in both men and women were trachea, bronchus and lung cancer, which account for 36.9% of all cancer-attributable deaths.

The most common cancers attributable to risk after these were colorectal cancer, esophageal cancer and stomach cancer in men, and cervical cancer, colorectal cancer and cancer breast in women.

“To our knowledge, this study represents the largest effort to date to determine the global burden of cancer attributable to risk factors,” the authors state.

“These findings underscore that a significant proportion of the global cancer burden could be prevented through interventions aimed at reducing exposure to known cancer risk factors,” they add.

“Our findings can help policy makers and researchers identify key risk factors that could be targeted as part of efforts to reduce cancer deaths and ill health at regional, national and global levels,” says one of the co-authors, Dr. Christopher Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington’s School of Medicine Medicine) in Seattle, in a statement.

These findings come from an analysis of the Global Burden of Disease, Injury and Risk Factors Study 2019, an innovative project designed to quantify the burden of cancer attributable to a wide range of modifiable risk factors in countries around the world, taking into account factors such as age and gender, and how they change over time.

Outcomes, including cancer deaths and Disability-Adjusted Life-Years (DALYs), were assessed for 82 risk-outcome pairs, with 23 cancer types and 34 risk factors. known risk, in the categories of behavioural, environmental, occupational and metabolic risk factors, based on the criteria of the World Cancer Research Fund.

The results were assessed for the year 2019, and the evolution of the results over time was assessed based on the changes observed between 2010 and 2019.

Overall, the assessed risk factors were responsible for 44.4% of all cancer deaths. The remaining cancers probably could not be prevented by controlling the risk factors assessed in this study.

Among men, assessed risk factors were responsible for about half (50.6%) of all cancer deaths, while the proportion was lower among women, about a third (36.3% ).

In 2019, the main global risk factors for both sexes were behavioral, and the most important were smoking, alcohol consumption and a high BMI, although some differences were identified between the sexes.

Cancer DALYs attributable to smoking, for example, were higher in males than females (33.2% versus 8.9%), as were DALYs attributable to alcohol (7.4% versus 2. 3%).

Men were also more likely to have cancer deaths and DALYs attributable to environmental and occupational risks, as well as behavioral risks, compared to women.

Smoking, alcohol consumption and a high BMI were the main contributors in higher income regions according to their sociodemographic index.

However, in low-income areas, the major risk factors for cancer death attributable to risk were smoking, unprotected sex, and alcohol consumption.

Increase over time

Overall, the rate of cancer deaths associated with assessed risks increased by 20.4% between 2010 and 2019.

Importantly, the increases observed over this period were greatest for the cancer burden attributed to metabolic risks, which increased by 34.7% for cancer deaths.

The authors note that increases in metabolic risks, such as obesity, were largely due to increases in low- and low-to-middle income countries and may, in fact, be a perverse effect of their progress.