Four in 10 cancer cases preventable globally — WHO

Nearly four in every ten cancer cases worldwide are linked to preventable risk factors, the World Health Organisation (WHO) has warned, urging countries to step up investment in prevention strategies that could save millions of lives.

The WHO disclosed this on Tuesday in a statement releasing a new global analysis conducted with its International Agency for Research on Cancer (IARC), ahead of World Cancer Day on February 4.

According to the report, about 37 per cent of all new cancer cases diagnosed in 2022 — roughly 7.1 million cases — were attributed to preventable causes such as tobacco use, alcohol consumption, obesity, physical inactivity, air pollution, ultraviolet radiation and cancer-causing infections.

Describing the findings as a wake-up call, WHO Team Lead for Cancer Control, Dr André Ilbawi, said many cancers are not inevitable.

“This is the first global analysis to demonstrate, at this scale, how much cancer risk comes from causes we can prevent,” Ilbawi said. “The data provides governments and individuals with actionable evidence to stop many cancers before they start.”

The study, which analysed data from 185 countries and 36 cancer types, identified tobacco use as the leading preventable cause, responsible for 15 per cent of new cancer cases globally. Infections accounted for 10 per cent, while alcohol consumption contributed three per cent.

Ilbawi said focusing on these major risk factors alone could significantly reduce the global cancer burden.

“By addressing tobacco use, infections and alcohol consumption, countries could dramatically cut cancer rates,” he noted.

Lung, stomach and cervical cancers were found to make up nearly half of all preventable cases. Lung cancer was largely linked to smoking and air pollution, stomach cancer to Helicobacter pylori infection, and cervical cancer primarily to human papillomavirus (HPV).

“This study confirms that vaccines, clean air and healthier lifestyles are powerful cancer-prevention tools,” Ilbawi added.

The burden of preventable cancer was also higher among men. About 45 per cent of new cancer cases in men were linked to preventable causes, compared with 30 per cent among women.

Smoking alone accounted for 23 per cent of new cancer cases in men, followed by infections and alcohol. Among women, infections were the leading risk factor, followed by smoking and high body mass index.

Deputy Head of the IARC Cancer Surveillance Unit and senior author of the study, Dr Isabelle Soerjomataram, stressed the need for stronger prevention-focused policies.

“This landmark analysis shows that tackling preventable causes remains one of the most powerful ways to reduce the global cancer burden,” she said. “Prevention is not optional — it is essential.”

She added that cancer prevention requires action beyond the health sector, including stronger tobacco and alcohol regulations, vaccination programmes, cleaner air, safer workplaces and healthier food environments.

The report also highlighted significant regional differences. Among women, preventable cancer cases ranged from 24 per cent in North Africa and West Asia to 38 per cent in sub-Saharan Africa. Among men, East Asia recorded the highest burden at 57 per cent.

According to the WHO, these disparities reflect differences in exposure to risk factors, national prevention policies and the strength of health systems.

The organisation called for coordinated global action, noting that preventing cancer would not only save lives but also reduce healthcare costs and improve overall wellbeing.

“Cancer prevention is a shared responsibility. When governments act early, millions of families can be spared the physical, emotional and financial burden of a cancer diagnosis,” Ilbawi said.