Cancer is the second largest cause of death in the world (second only to cardiovascular disease), and exposure to risk factors plays an important role in many cancer types. So, which risk factors are the most worthy of attention?
Last month, a large-scale global study published on The Lancet gave the latest answers: Nearly half of the world's cancer (44.4%) deaths can be traced back to 34 known risk factors, ranking in the top three in smoking, drinking and obesity. These variable risk factors have increased 20% of deaths compared to 2010.
study also found that the ranking of cancer risk factors for men and women is different. For men, the top three ranks were tobacco, alcohol and dietary risks, while among women, tobacco, unsafe sexual behaviors and dietary risks.
Globally, most cancer deaths and disability-adjusted life year (DALY) can be attributed to to alterable cancer risk factors, where behavioral risk is the largest risk factor. The researchers analyzed data from the 2019 Global Burden of Disease, Injury, and Risk Factors Study (GBD 2019) to assess the modifiable risk factors for the global cancer burden. This is the only cancer burden study to date that targets variable risk factors in all countries around the world.
According to the standards of World Cancer Research Foundation , the study analyzed 82 risk result pairings (including 23 cancer types and 34 risk factors), and was divided into three groups: environment and occupation, behavior, and metabolism. The researchers also compared the number of cancer deaths and the changes in DALY between 2010 and 2019.
Main results
(1) Nearly half of the world's cancer deaths can be attributed to risk factors
2019, the total number of cancer deaths caused by all estimated risk factors worldwide was 4.45 million, and the total number of men and women accounted for 44.4% of all cancer deaths. The total number of all cancer DALYs attributable to risk factors worldwide is 105 million, and the total number of men and women accounts for 42% of all cancer DALYs.
(2) In terms of cancer risk factors ranking, there are differences between men and women
Overall, the main risk factors for global attributable cancer death and DALY are smoking, alcohol consumption and high BMI.
The main risk factor for men is tobacco, accounting for 33.9% of all cancer DALYs in men, followed by alcohol, dietary risk and air pollution, accounting for 7.4%, 5.9% and 4.4% respectively.
For women, the main risk factor is tobacco, accounting for 10.7% of all cancer DALYs in women. Unsafe sexual behavior is the second largest risk factor for women, accounting for 8.2%, followed by dietary risk, high BMI and high fasting blood sugar, accounting for 5.1%, 4.7%, and 3.6%, respectively.
(3) Tracheal cancer, bronchial cancer and lung cancer are most related to cancer risk factors
2019, the main cancers that cause deaths from cancer risk factors in men and women around the world are tracheal cancer, bronchial cancer and lung cancer, accounting for 36·9% of all attributable cancer deaths. Secondly, in men, rectal cancer, esophageal cancer, and gastric cancer, , and in women, cervical cancer, , colorectal cancer, and breast cancer, .
(4) Global attributable cancer deaths increased by 20.4%
Compared with 2010, the global attributable cancer deaths increased by 20.4% in 2019, and cancer DALY increased by 16.8%. Among them, the largest percentage increase was metabolic-related risks, with cancer death and DALY increased by 34.7% and 33.3% respectively; cancer death and DALY attributable to behavioral risk increased by 17.9% and 14.4% respectively; cancer death and DALY attributable to environmental and occupational risk increased by 16.7% and 13.1% respectively.
These findings highlight the possibility that some global cancer burden can be prevented by interventions that reduce known cancer risk factors, such as early diagnosis and effective cancer treatment.
