Two Lifestyle Habits Cause Nearly 40 Percent of Preventable Cancers

The Stark Reality of Preventable Cancer

Nearly 40 percent of all cancer cases globally are preventable, with 7.1 million new cancer cases in 2022 linked to modifiable risk factors . This groundbreaking finding from the World Health Organization reveals that millions of cancer diagnoses could be avoided through lifestyle changes and public health interventions.

Smoking leads the pack as the most dangerous preventable risk factor, contributing to 15.1 percent of all new cancer cases, followed by infections at 10.2 percent and alcohol consumption at 3.2 percent . Alcohol alone accounted for approximately 700,000 cancer cases globally , while lung, stomach and cervical cancers represented nearly half of all preventable cancer cases .

The research analyzed data from 185 countries and examined 30 different modifiable risk factors, providing the most comprehensive global picture of preventable cancer to date. "Addressing these preventable causes represents one of the most powerful opportunities to reduce the global cancer burden," says Isabelle Soerjomataram, medical epidemiologist at WHO .

Smoking Remains the Dominant Threat

Tobacco use causes more than 440,000 premature deaths from cancer and other causes each year in the United States alone and is responsible for approximately 30 percent of all cancer-related deaths . Cigarette smoking increases the risk of lung cancer by at least 10-fold and as much as 20-fold, depending on smoking habits and history .

The geographic impact varies dramatically. In East Asia, about 15 percent of all lung cancer cases in women were due to air pollution, while in Northern Africa and Western Asia, approximately 20 percent of all lung cancer cases in men were due to air pollution . Despite decades of anti-smoking campaigns, smoking continues to dominate preventable cancer deaths worldwide.

The encouraging news is that lung cancer is largely preventable, with almost 9 out of 10 cases preventable if current smokers quit, and after 10 years of quitting smoking, the risk of lung cancer falls to about half that of a smoker .

Alcohol's Hidden Cancer Connection

There is strong scientific evidence that alcohol drinking can cause cancer, with the International Agency for Research on Cancer classifying alcohol as a Group 1 carcinogen in 1987 . Current evidence suggests that there is no threshold of alcohol consumption below which cancer risk does not increase, at least for some cancers .

Even light drinkers face increased risk - women who have just one drink per day have a higher risk of breast cancer than those who have less than one drink a week . Almost 11 percent of all cancer cases causally linked to alcohol were due to drinking no more than 1 large bottle of beer, 2 glasses of wine, or 60 ml of spirits per day .

While many people understand the risks of developing cancer associated with smoking, many remain unaware that alcohol also causes cancer, and most U.S. adults are unaware of the alcohol-cancer link . This knowledge gap represents a critical opportunity for public health education.

A Path Forward Through Prevention

"By examining patterns across countries and population groups, we can provide governments and individuals with more specific information to help prevent many cancer cases before they start," says André Ilbawi, WHO Team Lead for Cancer Control . The research reveals that prevention strategies must be tailored to regional patterns and demographics.

Among women, infections caused the highest number of preventable cancers with 2.7 million cases, while among men, behavioral risk factors like smoking tobacco caused 4.3 million cases . The largest share of preventable cancers in women was due to high-risk human papillomavirus (HPV), which can lead to cervical cancer, yet HPV vaccine coverage remains low in many parts of the world despite preventing 90 percent of HPV-related cancers .

The findings underscore that cancer prevention isn't just about individual choices - it requires comprehensive policy approaches addressing tobacco control, alcohol taxation, vaccination programs, and environmental regulations. As researchers continue to map the complex relationship between lifestyle and cancer risk, the message remains clear: nearly four in ten cancer cases need never happen.