Global and regional cancer burden attributable to modifiable risk factors in 2022: Evidence to guide cancer prevention

Cancer remains a leading cause of morbidity globally, largely driven by modifiable risk factors. We provide estimates of the global and national cancer burden attributable to these factors, namely tobacco smoking, alcohol consumption, high body mass index (BMI), insufficient physical activity, smokeless tobacco and areca nut, suboptimal breastfeeding, air pollution, ultraviolet radiation (UVR), infections (due to nine agents), and occupational (due to 13 agents) exposures to inform prevention efforts. We estimated 2022 cancer cases attributable to 30 modifiable risk factors in 185 countries using GLOBOCAN data for 36 cancer sites. Risk factors were grouped as behavioural, environmental, infectious, or occupational, with prevalence data from around 2012 to reflect latency between exposure and cancer diagnosis. Population-attributable fractions (PAFs) were estimated using the Levin or Miettinen formulas, or derived directly from prevalence data where applicable, and adjusted for cancer subtypes when relevant. Combined PAFs accounting for overlapping exposures were derived by cancer, sex, country, and region. In 2022, an estimated 7.1 million of 18.7 million new cancer cases (37.8%) worldwide were attributable to 30 modifiable risk factors – 2.7 million (29.7%) in women and 4.3 million (45.4%) in men. The proportion of preventable cancers varied across regions and by sex, ranging from 24.6% of all new cancer cases in Northern Africa and Western Asia to 38.2% in sub-Saharan Africa for women and from 28.1% in Latin America & the Caribbean to 57.2% in East Asia for men. Smoking, infections, and alcohol consumption were the leading contributors to cancer burden globally, accounting for 15.1%, 10.2%, and 3.2% of all new cancer cases, respectively. Lung, stomach, and cervical cancers showed the greatest potential for prevention, together representing nearly half of all preventable cancers. Reducing exposure to modifiable risk factors offers major opportunities for cancer prevention worldwide, underscoring the importance of tailored, evidence-based and gender-sensitive strategies across populations.