Nearly 40% of new cancer cases worldwide are potentially preventable, according to a landmark analysis released today, . The study, published in Nature Medicine, analyzed dozens of cancer types across almost 200 countries, revealing that roughly seven million cancer diagnoses in 2022 were linked to modifiable risk factors – those that can be changed or managed to reduce the likelihood of developing the disease.
The leading contributor to preventable cancer cases globally is tobacco smoking, accounting for approximately 15% of cases, or 3.3 million diagnoses. This represents followed by infections, responsible for over 10% (2.3 million cases), and alcohol consumption, linked to more than 3% of preventable cancers.
A Significant Proportion of Cases Linked to Lifestyle and Environmental Factors
The analysis identified 30 modifiable risk factors, including, for the first time, nine types of infections. This comprehensive approach allows for a more nuanced understanding of cancer prevention than previous studies, which often focused on single risk factors or mortality rates rather than incidence.
Researchers combined global case data from 2022 for 36 different cancers across 185 countries with data from 2012 detailing people’s exposure to each risk factor. This allowed them to estimate the proportion of cases directly linked to each factor. The findings underscore the powerful potential of avoiding these risk factors to reduce the future burden of cancer, according to study co-author Hanna Fink, a cancer epidemiologist at the World Health Organization’s International Agency for Research on Cancer in Lyon, France.
Specific Cancers Heavily Influenced by Preventable Factors
Lung, stomach, and cervical cancers comprised nearly half of all preventable cancer cases identified in the study. This highlights the significant impact that targeted prevention strategies could have on these specific cancer types. The study also noted differences in preventable cancer cases between sexes, with more cases affecting the male population.
The Importance of Addressing Modifiable Risk Factors
While cancer remains a leading cause of illness and death worldwide, and cases are expected to rise in coming decades if current trends continue, the study offers a hopeful message. Previous research estimated that around 44% of global cancer deaths are attributable to avoidable or controllable causes. This new analysis focuses on the preventability of cancer cases, rather than deaths, providing a more complete picture of the potential for intervention.
The 30 modifiable risk factors considered in the study include well-established causes of cancer such as tobacco smoking, alcohol consumption, and infections, as well as factors like a high body mass index (BMI), insufficient physical activity, smokeless tobacco and areca nut use, certain breastfeeding practices, and exposure to ultraviolet radiation. The inclusion of infectious agents, such as hepatitis B and human papillomavirus (HPV), represents a significant advancement in understanding preventable cancer risks.
Implications for Public Health and Future Research
The findings emphasize the importance of public health initiatives aimed at reducing exposure to modifiable risk factors. These initiatives could include policies to discourage smoking and alcohol consumption, vaccination programs to prevent infections like HPV and hepatitis B, and efforts to promote healthy lifestyles through diet and exercise.
“We now have the information to prevent cancer before it starts,” said Isabelle Soerjomataram, a cancer surveillance specialist at the International Agency on Research on Cancer. However, she also acknowledged that effective prevention depends on access to healthcare resources, which varies significantly around the world.
The study’s authors hope that these findings will inform future cancer prevention strategies and ultimately lead to a reduction in the global cancer burden. The analysis, released ahead of World Cancer Day , serves as a critical reminder of the power of prevention in the fight against cancer.
According to data analyzed, cigarette smoking accounted for 19.3% of all cancer cases, contributing to 56.0% of all potentially preventable cancers in men and 39.9% in women.
