An international scientific group presented the results of estimates for 185 countries, according to which 2.3 million women will fall ill with breast cancer in 2022, and 670 thousand will die from it, and by 2050 these figures will increase to 3.2 million and 1.1 million, respectively. The researchers' findings are published in Nature Medicine.
Breast cancer is the leading cause of cancer incidence and mortality among women, and the second leading cause of cancer incidence and fourth leading cause of mortality among the general population. To reduce the number of premature deaths from this disease worldwide and the survival deficit in certain regions, the World Health Organization launched the Global Breast Cancer Initiative (GBCI) in 2021. Its stated goal is to reduce mortality by 2.5 percent annually, which requires early detection (more than 60 percent at stages I and II), timely diagnosis (more than 80 percent of confirmations within two months of the first examination), and adequate patient management (more than 80 percent of treatment completions). The implementation of this and other programs requires accurate data on the current burden of the disease and its assessment for the future.
Miranda Fidler-Benaoudia of the University of Calgary and colleagues from Australia, Canada, Kenya, the United States and France estimated breast cancer incidence and mortality in 185 countries for 2022 and 2050 using the International Agency for Research on Cancer (IARC) GLOBOCAN database and 10-year trends in incidence from the CI5plus database and mortality from the WHO. The estimates were global, regional and age-specific; they excluded cases in men.
According to the researchers’ calculations, in 2022, 2.3 million new cases of breast cancer developed in 185 countries and 670 thousand deaths occurred from it. This tumor occupied the first or second place in the structure of oncological incidence in 183 and mortality in 169 countries. At the same time, its burden in different regions of the world was very uneven and could differ by almost four times. The number of new cases was highest in Australia and New Zealand (100.3 per 100 thousand), followed by North America and Northern Europe, and the lowest in South and Central Asia (26.7 per 100 thousand), East and Central Africa. In terms of mortality, Melanesia (26.8 per 100 thousand), Polynesia and West Africa were in the lead, and the lowest rates were in East Asia (6.5 per 100 thousand), Central and North America.
The mortality-to-incidence ratio tended to increase with decreasing human development index (HDI) of a country: from 17 percent at very high HDI to 56 percent at low HDI. It is estimated that, on average, one in 20 women will be diagnosed with breast cancer in her lifetime, and one in 70 will die from it. At current rates, by 2050 new cases of this cancer will increase by 38 percent to 3.2 million, and deaths from it by 68 percent to 1.1 million.
Of the 50 countries with at least 10 years of high-quality CI5plus data, new breast cancer cases increased in 27 (54%) over that period. The largest annual increases were seen in Bahrain (4.8%), South Korea and Japan, and in the under-50 age group alone in Ecuador (4.1%), Slovenia and Croatia. Only three countries – Argentina, Germany and Denmark – showed significant declines, and only in those aged 50 and over. Of the 46 countries with high-quality 10-year mortality data, 30 showed declines. Seven countries met the GBCI target of a 2.5% annual mortality reduction: Malta (3.8%), Denmark, Belgium, Switzerland, Lithuania, the Netherlands and Slovenia. Rates between 2.1 and 2.4 percent were also recorded in Norway, Sweden, Ireland, Australia, the United Kingdom and New Zealand.
Thus, the dynamics of breast cancer incidence and mortality from it vary greatly in different regions of the world, and despite the targets set by the WHO, these indicators will grow, mainly due to countries with medium and low HDI levels, where the maximum amount of efforts are needed to combat the disease, the authors of the study conclude.
An earlier analysis of IARC data for the same 185 countries showed that by 2050, overall cancer incidence will increase by 77 percent and mortality by 90 percent.
