News release

From: Springer Nature

Cancer: Quantifying the global preventable cancer burden

Nearly 40% of new cancer cases worldwide in 2022 may be associated with modifiable risk factors, according to an analysis of 36 cancer types from 185 countries, published in Nature Medicine. The findings suggest that reducing exposures such as tobacco smoking, certain infections, and alcohol use remains essential for cancer prevention.

Cancer is a leading cause of illness and death around the world, and its burden varies across regions partly because populations are exposed to different modifiable risk factors. These include behavioural, environmental, infectious, and work-related risks — which are potentially preventable. Understanding how the global cancer burden may relate to these risk factors can help countries to plan prevention programmes suited to their own priorities.

Hanna Fink and colleagues estimated the global and national cancer burden that may be attributable to 30 modifiable risk factors. They combined incidence data from 2022 (from 36 types of cancer across 185 countries) with how common these exposures were about 10 years earlier. They then calculated the associations between cases and each risk factor while acknowledging that some risk factors can occur together. According to the authors, in total about 7.1 million of the 18.7 million new cancer cases (37.8%) in 2022 were potentially attributable to these modifiable risk factors, including 2.7 million (29.7%) in women and 4.3 million (45.4%) in men. Tobacco smoking (15.1%), infections (10.2%), and alcohol consumption (3.2%) were the leading contributors, and lung, stomach, and cervical cancers were estimated to constitute nearly half of these potentially preventable cases.

For women across the globe, infections such as those caused by human papillomavirus (HPV) or Helicobacter pylori appeared to be the biggest risk factor for cancers, and were associated with 11.5% of cases. Whereas for men globally the biggest risk factor was smoking, which was associated with 23.1% of cases. The authors also highlight various geographic trends. For example, women in sub-Saharan Africa appeared to have the highest burden of cancer associated with modifiable risk factors (38.2% of cases), while women in Northern Africa and Western Asia had the lowest burden (24.6% of cases). Meanwhile, 57.2% of cancer cases in men in East Asia were associated with modifiable risk factors, compared to 28.1% of cases for men in Latin America and the Caribbean.

The findings highlight potential opportunities for cancer prevention, including tobacco control, preventing infections, and nationally adapted strategies suited to each region. The authors note that data quality and availability vary widely across regions, with particularly large gaps in low and middle income countries where cancer and risk factor data are often limited. Better surveillance and more detailed data would help strengthen future estimates and improve policy guidance, they conclude.