Cancer incidence and mortality are rapidly increasing worldwide, but a large-scale analysis has revealed that global responses remain insufficient.
According to a study published on the 7th (local time) in the international medical journal ⟪The Lancet⟫, the number of new cancer patients worldwide has more than doubled since 1990, reaching 18.5 million as of 2023. During the same period, annual cancer deaths increased by 74%, totaling 10.4 million. Non-melanoma skin cancer was excluded from this analysis.
The research team from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington and the Global Burden of Disease Study cancer collaboration analyzed cancer registration data, mortality statistics, and family and caregiver interview data from 204 countries and regions worldwide from 1990 to 2023, examining 47 types of cancer and 44 risk factors. They also predicted cancer incidence and mortality up to 2050 based on the same data.
Surge in Cancer Burden Since 1990... The Increase is Centered in Low- and Middle-Income Countries
The analysis found that the global cancer burden has steadily increased over the past 30 years. As of 2023, there are 18.5 million new cancer patients and 10.4 million deaths, representing increases of 105% and 74%, respectively, compared to 1990. The majority of current cancer patients are concentrated in low- and middle-income countries, where the rate of increase is also the steepest.
While age-standardized mortality rates, which eliminate the effects of age structure, show a decreasing trend globally, this improvement is primarily limited to high-income and upper-middle-income countries. In contrast, both cancer incidence and mortality rates continue to rise in low-income and lower-middle-income countries.
30 Million Cancer Diagnoses Annually by 2050... Population Aging is a Key Factor
The research team predicts that if current trends continue, the number of new cancer patients worldwide will increase by an additional 61% over the next 25 years, reaching 30.5 million annually by 2050. Cancer deaths are expected to rise by about 75% during the same period, reaching 18.6 million annually.
However, the researchers explained that this increase is not due to a rapid deterioration in individual cancer risk but rather is primarily caused by global population growth and aging. In fact, based on age-adjusted standards, future cancer incidence and mortality rates are not expected to rise significantly worldwide.
Nevertheless, the researchers pointed out that these changes fall far short of the United Nations Sustainable Development Goals (SDG) to reduce premature deaths from non-communicable diseases by one-third by 2030.
4 Out of 10 Cancer Deaths Linked to ‘Modifiable Risk Factors’
One of the most notable findings of this study is that a significant portion of cancer deaths is preventable. Among the 10.4 million cancer deaths in 2023, approximately 4.3 million, or 42%, are estimated to be associated with 44 modifiable risk factors.
Behavioral factors accounted for the largest share across all income levels. Smoking accounted for 21% of global cancer deaths and was the most significant risk factor in all income groups except low-income countries. In low-income countries, unsafe sexual practices were associated with 13% of cancer deaths, representing the largest share.
Gender differences were also evident. For men, 46% of cancer deaths were linked to smoking, an unbalanced diet, excessive alcohol consumption, occupational hazards, and air pollution, while for women, 36% were related to smoking, unsafe sexual practices, obesity, high blood sugar, and dietary habits.
Researchers Urge Immediate Strengthening of Cancer Prevention, Early Diagnosis, and Treatment Accessibility
Dr. Lisa Fors, the lead author from IHME, stated, “Cancer continues to occupy a central position in the global disease burden and is expected to increase significantly in resource-limited countries over the coming decades. Nevertheless, cancer management policies are still not sufficiently prioritized in the global health agenda.”
Co-author Dr. Theo Boss emphasized, “The fact that 4 out of 10 cancer deaths are already associated with established risk factors shows that a significant number of cancers can be prevented through individual efforts and population-level public health interventions.”
The researchers particularly pointed out the urgent need to integrate cancer prevention policies into health systems in low- and middle-income countries and to enhance accessibility to early diagnosis and effective treatment.
Data Gaps Persist... Actual Cancer Burden May Be Greater
The researchers noted that while this analysis was based on the best available data, some limitations exist. In resource-limited countries, the quality of cancer registration and mortality statistics is insufficient, and infectious diseases that increase cancer risk, such as Helicobacter pylori and schistosomiasis, were not included in the analysis. This may have led to an underestimation of preventable cancer deaths.
Additionally, the impact of the COVID-19 pandemic, recent armed conflicts, and future advancements in treatment technologies on cancer incidence and mortality was not reflected in this prediction.
The researchers emphasized, “To slow the increase in cancer burden, decisive policy decisions and investments, as well as global cooperation considering equity, are critical at this point. The future of cancer management depends on today’s choices.”
