"The Lancet": Tobacco and alcohol are the number one carcinogenic "murderer" real hammer! Data from the largest global burden of disease study to date show that more than 40% of cancers are associated with preventable carcinogenic risk factors such as alcohol and tobacco

*For medical professionals only

Cancer is currently the second leading cause of death in the world (the first is cardiovascular disease)[1], and the incidence of cancer in young people is on the rise

In fact, about 30%-50% of cancers are preventable

However, there are so many controllable factors, which are the keys to cancer prevention?

According to a recent study published in The Lancet, smoking and alcohol consumption are the world's top two carcinogenic risk factors, and nearly 4.

Screenshot of the first page of the article

In 2020, about 10 million people died of cancer worldwide, accounting for nearly one in six deaths worldwide

A comprehensive understanding of the cancer burden caused by carcinogenic risk factors and their changing trends is critical

In addition to the number of cancer deaths, the study added disability-adjusted life-years (DALYs) as a measure, providing a new perspective

The researchers selected 34 common carcinogenic risk factors from the GBD 2019 report, as well as 23 cancer types associated with these risk factors, to form a total of 82 pairs of risk-cancer outcomes to assess

Some of the findings are expressed in socio-demographic index (SDI), which is a composite index
calculated based on the total fertility rate of women under the age of 25, per capita disposable income, and the average educational attainment of individuals aged 15 and over.

The index ranges from 0 (low SDI) to 100 (high SDI), and its quintile intervals are used to represent low, low-medium, medium, medium-high, and high SDI countries
, respectively.

The findings suggest that 4.
45 million (95% UI, 401-494) cancer deaths worldwide in 2019 can be attributed to carcinogenic risk factors, accounting for 44.
4% (41.
3-48.
4) of total cancer deaths
.

Among them, the number of male cancer deaths attributable to carcinogenic risk factors was 2.
88 million (260-318), accounting for 50.
6% (47.
8-54.
1); the number of female cancer deaths attributable to carcinogenic risk factors was 1.
58 million (1.
36-1.
84), accounting for 36.
3% (32.
5-41.
3)
of the total.

Global cancer burden attributable risk factor analysis

Of the cancer-related DALYs globally in 2019, 1.
05 (0.
95-1.
16) million years can be attributed to carcinogenic risk factors, accounting for 42.
0% (39.
1-45.
6)
of all cancer-related DALYs.

Among them, male cancer DALYs were 67.
5 million years (6080-7510), accounting for 48.
0% (45.
3-51.
5); female cancers DALYs were 37.
6 million years (3280-4310), accounting for 34.
3% (30.
9-38.
7).

For men, the leading carcinogenic risk factor is smoking, which accounted for 33.
9% (32.
3-35.
4)
of the total number of male cancer DALYs attributed to risk factors globally in 2019.

Drinking, dietary risk and air pollution were 7.
4% (6.
7-8.
2), 5.
9% (4.
4-8.
3) and 4.
4% (3.
4-5.
5),
respectively.

The number one risk factor for women is also smoking, accounting for 10.
7% (9.
9–11.
5)
of the total number of female cancer DALYs attributed to risk factors globally in 2019.

In second place were unsafe sex at 8.
2% (7.
0-8.
8), followed by dietary risk (5.
1%, 95% UI 4.
0-6.
7), high BMI (4.
7%, 95% UI 2.
8-7.
0) and high fasting blood glucose (3.
6%, 95% UI 1.
0-7.
5).

Next, the researchers assessed
the cancer burden attributed to carcinogenic risk factors from multiple aspects, such as cancer type, sex, regional distribution, age, and SDI.

Of the cancer deaths attributed to risk factors globally, lung cancer (including lung, trachea and bronchi, 36.
9% total) accounted for the largest proportion of cancer deaths, followed by colon and rectal cancer (13.
3%), esophageal cancer (9.
7%), and stomach cancer (6.
6%); The highest proportion of women were cervical cancer (17.
9%), colon and rectal cancer (15.
8%), and breast cancer (11.
0%)
.

When sex-related cancers (e.
g.
, cervical cancer) are excluded, far more cancers attributable to carcinogenic risk factors have died in men than in women; However, this proportion of men to women in countries with high SDI tends to be smaller than in countries with
low SDI.

In addition, while countries with high SDI account for only 13.
1% of the global population, these countries account for 25.
4% of the total number of cancer deaths globally and 26.
5%
of cancer deaths attributed to carcinogenic risk factors.

Analytics of attributable risk factors for cancer death based on sex and SDI

In terms of geographical distribution, the burden of cancer attributed to carcinogenic risk factors is generally higher in some high-income regions of North America and Europe; It is followed by East and South-East Asia, Latin America Southern and Southern Africa
.

In people of the same age, the burden of cancer caused by behavioral risk is much higher than other risk factors; And the burden of cancer increases
with age.

In addition, the burden of cancer attributed to risk factors was significantly higher in high-SDI regions (developed countries) than in low-SDI regions
.

Changes in cancer burden attributed to carcinogenic risk factors, in different SDI intervals and age groups

In addition, the researchers analyzed trends in data change between 2010 and 2019: The number of cancer deaths attributed to carcinogenic risk factors and DALYs increased by 20.
4% and 16.
8%, respectively, over the past decade, with the largest increase in the burden of cancer attributed to metabolic risk, especially in low-SDI countries
.

Changes in cancer burden attributed to environmental and occupational, behavioral, and metabolic risk factors in different SDI regions, 2010-2019

More notably, smoking and alcohol consumption were both the top two major carcinogenic risk factors
in 2010 and 2019.

In addition, the burden of cancer due to metabolic risk is on the rise and also needs to be vigilant
.

2010-2019, Top 11 Cancer Burden Attributable Risk Factor Analysis

Overall, this study shows that smoking and alcohol consumption remain major risk factors for the global cancer burden, and that countries need to tailor cancer prevention and control strategies to local conditions
.

What each of us can do is to develop good living habits, stay away from tobacco and alcohol, exercise properly, eat a reasonable diet, keep a good figure, and keep yourself away from cancer!

References:

1.
Sung H, Ferlay J, Siegel RL, et al.
Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries[J].
CA Cancer J Clin, 2021, 71(3):209-249.

2.
Tran K B, Lang J J, Compton K, et al.
The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019[J].
The Lancet, 2022, 400(10352): 563-591.

Responsible editor| Tan Shuo