Nearly half of all cancer deaths globally – 4.5 million out of approximately 10 million in 2022 – could have been avoided through preventative measures and improved treatment, according to a study published today in The Lancet Global Health. Researchers at the International Agency for Research on Cancer (IARC) identified primary prevention of key risk factors and enhancements in early detection and curative treatment as critical areas for intervention.
The study, utilizing a novel methodology developed at IARC, found that 3.1 million deaths (33%) were attributable to modifiable risk factors including tobacco use, alcohol consumption, excess body weight, infections, and exposure to ultraviolet radiation. An additional 1.4 million deaths (14%) could have been averted with improvements in early detection and access to effective cancer treatment.
Lung cancer presented the largest opportunity for preventative action, accounting for a significant proportion of deaths avoidable through primary prevention. Liver and stomach cancers likewise ranked highly in this category. However, the specific cancers most amenable to prevention varied depending on a country’s Human Development Index (HDI). Breast cancer, colorectal cancer, and prostate cancer were identified as the cancers where improvements in early detection and treatment could have the greatest impact.
The research highlighted substantial disparities in avoidable cancer mortality across different countries, regions, and HDI levels, with the greatest burden falling on nations with low and medium HDI scores. This suggests that socioeconomic factors play a crucial role in cancer outcomes.
The findings underscore the urgent demand for comprehensive national cancer control plans, particularly in low- and middle-income countries. Preventable cancers, such as cervical cancer, and treatable cancers, like breast cancer, disproportionately affect these settings. The study’s authors emphasize that scaling up primary prevention and improving early detection and treatment are essential to reducing the global cancer burden.
In higher-income countries, the study suggests a need to accelerate tobacco control efforts to further reduce lung cancer deaths. The research supports existing World Health Organization (WHO) initiatives, including “best buys” for tackling noncommunicable diseases, the WHO Framework Convention on Tobacco Control, and key global initiatives focused on breast and cervical cancer.
The IARC report estimates that the annual number of recent cancer cases will reach 35 million by 2050, a 77% increase from 2022. In 2022, there were almost 20 million new cancer cases globally, with lung cancer being the most frequently diagnosed, accounting for 12.4% of all cases. Breast cancer (11.6%) and colorectal cancer (9.6%) followed closely behind. Lung cancer was also the leading cause of cancer death, responsible for 18.7% of all cancer fatalities, followed by colorectal (9.3%) and liver cancer (7.8%).
