77% increase in new cancer cases by 2050, WHO predicts

Smoking remains the main risk factor for cancer, ahead of alcohol, obesity and air pollution. Disparities in access to care between countries fuel North-South inequalities.

Ahead of World Cancer Day on 4 February 2024, the World Health Organization's (WHO) International Agency for Research on Cancer (IARC) has released its latest forecasts for the evolution of cancers worldwide.[1].

According to these estimates, 20 million new cases of cancer and 9.7 million deaths would have been observed in 2022, compared to 14.1 million new cases and 8.2 million deaths in 2012. Taking into account population growth and ageing, the IARC estimates that this figure will increase to 35 million new cases of cancer in 2050, an increase of 77%. The number of deaths in 2050 would reach 18 million people, more than double the number in 2012.

Lung cancer tops list of deaths and new cases

Among the cancer cases recorded in 2022, ten types of cancer account for two-thirds of new cases. Lung cancer is the most common, with 2.5 million new cases (12.4 % of the total), followed by breast cancer, with 2.3 million new cases (11.6 %). Colorectal cancer (9.6 %), prostate cancer (7.3 %) and stomach cancer (4.9 %) come next.

Lung cancers are by far the most common murderers, with 1.8 million deaths (18.7 % of the total), followed by colorectal cancers (900,000 deaths, or 9.3 %), liver cancer (760,000 deaths, or 7.8 %), breast cancer (670,000 deaths, or 6.9 %) and stomach cancer (660,000 deaths, or 6.8 %). Lung cancer affects more men, while breast cancer is the leading cause of cancer and cancer death in women. The re-emergence of lung cancer as the most common cancer is thought to be due to changes in tobacco consumption, particularly in Asia.

Tobacco remains the first of risk factors linked to the onset of cancers, followed by alcohol, obesity and air pollution. The IARC data thus confirm the importance of the commercial determinants of health, that is to say the way in which private sector activities affect health. Thus the commercial determinants of health point more particularly to the role and responsibility of the tobacco industry in the tobacco epidemic.

Geographic health inequalities

Presented in parallel and covering 115 countries, the results of a WHO study on health coverage for cancer indicate that only 39 % of these countries cover the basic needs of their population in terms of cancer care. Access to basic cancer care is particularly reduced in low-income countries.

This issue of access to care is particularly true for breast cancer. In countries where the human development index (HDI) is very high, 1 in 12 women will be diagnosed with breast cancer and 1 in 71 will die from it. In countries where the HDI is very low, breast cancer will affect 1 in 28 women, and 1 in 48 will die from it. In these latter countries, women would be 50% less likely to be screened for breast cancer than in countries where the HDI is very high. They would die more from it due to late diagnosis and lack of access to appropriate treatment. A recent study evaluating the impact of active or passive smoking on breast cancer confirmed this significant disparity in access to care according to geographical areas.[2]. "The tools exist for governments to prioritize cancer care and ensure everyone has access to quality, affordable services. It's not just a question of resources, it's also a question of political will.", commented Dr Cary Adams, Director General of the Union for International Cancer Control (UICC).

Keywords: World Cancer Day, International Agency for Research on Cancer, World Health Organization, lung cancer, access to care

M.F.

[1] Global cancer burden growing, amidst mounting need for services, IARC, press release, published on 1^er February 2024, accessed February 2, 2024.

[2] Guo Q, Lu Y, Liu W, Lan G, Lan T, The global, regional, and national disease burden of breast cancer attributable to tobacco from 1990 to 2019: a global burden of disease study, BMC Public Health (2024) 24:107, published online: 06 January 2024.