Global Analysis: Four in Ten Cancer Cases Preventable

A recent global analysis conducted by the World Health Organization (WHO) and its International Agency for Research on Cancer (IARC) indicates that as many as four in ten cancer cases can potentially be avoided. This study closely examines 30 preventable factors contributing to cancer, including tobacco use, alcohol consumption, high body mass index, physical inactivity, air pollution, and ultraviolet radiation. Notably, it for the first time incorporates nine cancer-causing infections as potential risk factors.

In anticipation of World Cancer Day on February 4, the research highlights that approximately 37% of new cancer diagnoses in 2022—an estimated 7.1 million cases—were linked to preventable causes. This underscores the significant opportunity to lower the global cancer incidence through preventive measures.

The analysis, which draws on data from 185 countries and encompasses 36 different cancer types, identifies tobacco use as the leading preventable cause of cancer globally, accounting for around 15% of all new cancer cases. It is followed closely by infections at 10% and alcohol consumption at 3%.

Three specific types of cancer—lung, stomach, and cervical cancer—constitute close to half of all preventable cancer cases in both genders worldwide. Lung cancer primarily results from smoking and air pollution, stomach cancer is strongly linked to Helicobacter pylori infection, and cervical cancer is predominantly caused by human papillomavirus (HPV).

Dr. André Ilbawi, WHO Team Lead for Cancer Control and the study's author, emphasized the significance of this analysis, stating, “This is the first global analysis to show how much cancer risk comes from causes we can prevent. By examining patterns across countries and population groups, we can provide governments and individuals with more specific information to help prevent many cancer cases before they start.”

The burden of preventable cancer varies notably between genders and across different regions. The study reveals that the percentage of new cancer cases attributed to preventable causes is substantially higher in men at 45%, compared to 30% in women. In men, smoking is estimated to contribute to approximately 23% of new cancer cases, followed by infections at 9% and alcohol at 4%. For women, 11% of new cancer cases stem from infections, with smoking and high body mass index accounting for 6% and 3%, respectively.

Dr. Isabelle Soerjomataram, Deputy Head of the IARC Cancer Surveillance Unit and senior author of the study, described the research as a groundbreaking assessment of preventable cancer causes worldwide. She stated, “Addressing these preventable causes represents one of the most powerful opportunities to reduce the global cancer burden.”

When examining geographical variations, the findings indicate significant differences in preventable cancer cases. For women, this proportion varies from 24% in North Africa and West Asia to 38% in sub-Saharan Africa. Men in East Asia display the highest burden of preventable cancer at 57%, while Latin America and the Caribbean report the lowest at 28%. These disparities reflect diverse exposures to behavioral, environmental, occupational, and infectious risks, in addition to differences in socioeconomic development, national prevention policies, and healthcare system capabilities.

The study's results stress the importance of developing tailored prevention strategies that encompass robust tobacco control measures, alcohol regulation, vaccination against cancer-causing infections such as HPV and hepatitis B, enhancing air quality, ensuring safer workplaces, and fostering healthier environments for nutrition and physical activity.

Coordinated actions across multiple sectors, including health, education, energy, transportation, and labor, are essential to prevent millions from enduring the impact of a cancer diagnosis. By addressing these preventable risk factors, not only can the incidence of cancer be reduced, but long-term healthcare costs can also be decreased, thereby improving overall population health and well-being.