There has been a rapid increase in the global number of cancer cases and deaths between 1990 and 2023, despite advances in cancer treatment and efforts to tackle cancer risk factors over that same time period.
Without urgent action and targeted funding, 30.5 million people are forecast to receive a new cancer diagnosis and 18.6 million are expected to die from cancer in 2050, with over half of new cases and two-thirds of deaths occurring in low- and middle-income countries (LMICs).
This is according to a major new analysis from the Global Burden of Disease Study Cancer Collaborators, published in The Lancet. While the overall number of cancer cases and deaths is set to rise substantially from 2024 to 2050, encouragingly, when the global case and mortality rates are adjusted to account for differences in age, they are not forecast to increase. This suggests that most of the increases in cases and deaths will be due to population growth and the rise of ageing populations.
Such improvement, however, is still far away from the ambitious UN Sustainable Development Goal (SDG) to reduce premature mortality due to non-communicable diseases, which include cancer, by a third by 2030.
“Cancer remains an important contributor to disease burden globally and our study highlights how it is anticipated to grow substantially over the coming decades, with disproportionate growth in countries with limited resources,” said lead author Dr Lisa Force from the Institute for Health Metrics and Evaluation (IHME), University of Washington, USA. “Despite the clear need for action, cancer control policies and implementation remain underprioritised in global health, and there is insufficient funding to address this challenge in many settings.”
She added, “Ensuring equitable cancer outcomes globally will require greater efforts to reduce disparities in health service delivery such as access to accurate and timely diagnosis, and quality treatment and supportive care.”
Using data from population-based cancer registries, vital registration systems, and interviews with family members or caregivers of people who have died from cancer, the new analysis provides updated and extended global, regional, and national estimates from 1990 to 2023 in 204 countries and territories for 47 cancer types or groupings and 44 attributable risk factors. The analysis forecasts the cancer burden up to 2050 and examines cancer-specific progress thus far towards the UN SDG to reduce non-communicable disease deaths by a third between 2015 and 2030.
Striking differences in cancer burden around the world
Cancer deaths rose to 10.4 million and new cases jumped to 18.5 million globally in 2023 (both excluding non-melanoma skin cancers), increases of 74% and 105% respectively, since 1990.
However, recent global trends highlight stark disparities in the cancer burden. Although the age-standardised death rates decreased by 24% worldwide between 1990 and 2023, the reduction in rates appears to be driven by high- and upper-middle-income countries. Age-standardised rates of new cases worsened in low-income (up by 24%) and lower-middle-income countries (up by 29%), underscoring the disproportionate growth occurring in settings with lower resources (see table 1 in paper).
Between 1990 and 2023, Lebanon had the greatest percentage increase in age-standardised incidence and mortality rates for both sexes combined, while United Arab Emirates had the greatest decrease in age-standardised incidence, and Kazakhstan had the greatest decrease in age-standardised death rates.
In 2023, breast cancer was the most diagnosed cancer worldwide for both sexes combined, with tracheal, bronchus, and lung (TBL) cancer being the leading cause of cancer deaths.
Increasing impact of behavioural risk factors
The study estimates that 42% (4.3 million) of the estimated 10.4 million cancer deaths in 2023 were attributable to 44 potentially modifiable risk factors, presenting an opportunity for action.
Behavioural risk factors contributed to the most cancer deaths across all country income levels in 2023, especially tobacco use which contributed to 21% of cancer deaths globally. Tobacco was the leading risk factor in all country income levels except low-income countries, where the leading risk factor was unsafe sex (linked to 12.5% of all cancer deaths).
A greater proportion of global cancer deaths in men (46%) in 2023 were linked to potentially modifiable risk factors (mostly tobacco, unhealthy diet, high alcohol use, occupational risks, and air pollution) than in women (36%), for whom the leading risk factors were tobacco, unsafe sex, unhealthy diet, obesity, and high blood sugar.
“With four in 10 cancer deaths linked to established risk factors, including tobacco, poor diet, and high blood sugar, there are tremendous opportunities for countries to target these risk factors, potentially preventing cases of cancer and saving lives, alongside improving accurate and early diagnosis and treatment to support individuals who develop cancer,” said co-author Dr Theo Vos from IHME. “Reducing the burden of cancer across countries and worldwide demands both individual action and effective population-level approaches to reduce exposure to known risks.”
Equitable cancer-control efforts must be top priority
Ultimately, the study calls for cancer prevention to be a component of policies in LMICs and underscores the need for equitable cancer-control efforts to ensure all people with cancer receive the care they need where and when they need it.
“The rise of cancer in LMICs is an impending disaster,” said co-author Dr Meghnath Dhimal from the Nepal Health Research Council. “There are cost-effective interventions for cancer in countries at all stages of development. These cancer burden estimates can help broaden the discussion around the importance of cancer and other non-communicable diseases in the global health agenda. To control the growth of non-communicable diseases including cancer in LMICs, an interdisciplinary approach for evidence generation and multi-sectoral collaboration and coordination for implementation are urgently needed."
According to Dr Force, “These new estimates and forecasts can support governments and the global health community in developing data informed policies and actions to improve cancer control and outcomes around the world. They can also support tracking of progress towards global and regional cancer targets.”
Writing in a linked Comment, Dr Qingwei Luo and Dr David P Smith from The University of Sydney and Cancer Council NSW, who were not involved in the study, said: “To ensure meaningful progress in reducing the global cancer burden, it is imperative that governments prioritise funding, strengthen health systems, reduce inequalities, and invest in robust cancer control initiatives and research on prevention, intervention, and implementation, because the future of cancer control depends on decisive, collective action today.”
