Over one-third of new cancers could be prevented, WHO analysis finds

Of the 18.7 million people diagnosed with cancer in 2022, roughly 7.1 million cases could have been prevented. That's the finding from the World Health Organization's first global analysis of preventable cancer risk — and it reframes how we think about the disease.

The study, published in Nature Medicine in February, examined 36 types of cancer across 185 countries and identified 30 modifiable risk factors: tobacco, alcohol, air pollution, physical inactivity, and nine varieties of cancer-causing infections including HPV. The researchers found that about 37% of all cancer diagnoses that year were linked to at least one of these preventable causes.

"This is the first global analysis to show how much cancer risk comes from causes we can prevent," said André Ilbawi, a cancer surgery expert and WHO team lead for cancer control. The distinction matters. Some cancers stem from factors entirely outside our control — genetic inheritance, DNA changes that come with age. Others don't have to happen.

Tobacco smoking led the charge, responsible for 15% of all cancer diagnoses. Infections accounted for 10%, and alcohol for 3%. Lung, stomach, and cervical cancers made up nearly half of all preventable cases — which also means these are the cancers where intervention has the most immediate impact.

The picture shifts when you look across gender lines. In women, about 30% of cancer cases were preventable, with infections as the leading factor. In men, the number climbs to 45%, with tobacco smoking accounting for roughly 23% of diagnoses. That gap reflects both biological differences and different exposure patterns across populations.

What this opens up

Isabelle Soerjomataram, a cancer epidemiologist at the WHO's International Agency for Research on Cancer, called this "one of the most powerful opportunities to reduce the global cancer burden." The word "opportunity" is deliberate. This isn't about blame — it's about leverage. When you know what drives preventable cases, you can target interventions where they'll matter most.

Australia offers a concrete example. The country is on track to eliminate cervical cancer entirely by 2035, the first nation to achieve this. That's not because Australians are naturally immune. It's because of sustained vaccination programs and screening. The same principle applies globally: prevent HPV infection, prevent cervical cancer.

Ilbawi put it plainly: "The percentage of preventable cancers can change over time, and our goal is to get it as close to zero as possible." That's the trajectory this research maps out — not a distant ideal, but a measurable path forward.