Seven million cancers a year are preventable, WHO analysis finds

A WHO analysis estimates about 37% of cancers — roughly seven million cases a year — are linked to preventable infections, behaviours and environmental pollutants; smoking, infections and alcohol were the largest contributors.

WHO and the International Agency for Research on Cancer published the first global analysis estimating preventable cancers. The analysis reports that 37% of cancers worldwide — about seven million cases each year — are linked to infections, behaviours and environmental pollutants that can be avoided. The team analysed 30 known risk factors across 185 countries using cancer data from 2022 and exposure data from roughly a decade earlier. Researchers also noted some cancers result from ageing or inherited genes. Main findings: - About 37% of cancers globally (roughly seven million cases annually) were attributed to 30 preventable risk factors. - The largest contributors were tobacco smoking (about 3.3 million cases), infections (about 2.3 million) and alcohol use (about 700,000). - Patterns differ by sex and region: an estimated 45% of men's cancers and 30% of women's cancers were deemed preventable, and infections account for nearly 80% of preventable cases in sub‑Saharan African women. Summary: The report's authors described these results as a substantial opportunity to reduce the global cancer burden by addressing known causes. They noted that policies such as tobacco control and HPV vaccination have reduced risk in some places, and said the percentage of preventable cancers can change over time with a stated goal of lowering it further.