Breast Cancer
Breast cancer accounts for almost a quarter of new cancer cases among women.
Breast cancer is the leading cancer type in females in most countries in the world in 2018. (Map 1) About one in twenty females will be diagnosed with breast cancer over the course of their lifetime, although this number varies significantly by country. (Figure 1) There are large variations in estimated incidence rates worldwide, with an almost fourfold difference between the highest- and lowest-ranked regions. (Figure 2)
Figure 1. Cumulative risk of being diagnosed with female breast cancer by age 75 years, globally and in select countries. The cumulative risk of being diagnosed with female breast cancer by age 75 years (in percent) is 3% in India; 4% in Zimbabwe; 5% in Colombia; 9% in the US; 10% in the UK; and 5% globally.
Figure 2. Female breast cancer incidence and mortality rates, 2018. Age-standardized rate (world) per 100,000. In 2018, the breast cancer incidence and mortality age-standardized rates (world) per 100,000 were: Australia and New Zealand: 94.2 (incidence), 12.6 (mortality); Western Europe: 92.6 (incidence), 15.5 (mortality); Northern Europe: 90.1 (incidence), 14.1 (mortality); North America: 84.8 (incidence), 12.6 (mortality); Southern Europe: 80.3 (incidence), 13.3 (mortality); Polynesia: 70.5 (incidence), 21.6 (mortality); South America: 56.8 (incidence), 13.4 (mortality); Central and Eastern Europe: 54.5 (incidence), 15.5 (mortality); Caribbean: 50.2 (incidence), 18.1 (mortality); Melanesia: 49.7 (incidence), 25.5 (mortality); Northern Africa: 48.9 (incidence), 18.4 (mortality); World: 46.3 (incidence), 13 (mortality); Southern Africa: 46.2 (incidence), 15.6 (mortality); Western Asia: 45.3 (incidence), 13.6 (mortality); Micronesia: 42.5 (incidence), 16.3 (mortality); Eastern Asia: 39.2 (incidence), 8.6 (mortality); Central America: 38.3 (incidence), 10.1 (mortality); South-Eastern Asia: 38.1 (incidence), 14.1 (mortality); Western Africa: 37.3 (incidence), 17.8 (mortality); Eastern Africa: 29.9 (incidence), 15.4 (mortality); Middle Africa: 27.9 (incidence), 15.8 (mortality); South-Central Asia: 25.9 (incidence), 13.6 (mortality).
Incidence rates are elevated in Australia/New Zealand, Europe and North America, notably in Belgium (113 cases per 100,000 female population) and Luxembourg (109) in Europe, and in Australia (94). In contrast, incidence rates in sub-Saharan African regions, particularly in Eastern (30 cases per 100,000 female population) and Middle Africa (28), as well as South Central Asia (26), were considerably lower. Geographic variation is less pronounced for mortality rates, with the highest rates seen in Melanesia (26 deaths per 100,000 female population) and Polynesia (22), as well as in Northern and Western Africa (18). Notably, some countries in Europe, North America, and Oceania have among the lowest mortality rates despite their high incidence rates.
In lower-resource settings, breast and cervical cancer disproportionately affect women in the prime of life, resulting in significant economic and societal impact. A woman’s country… should not be allowed to influence the likelihood of dying from these cancers.
The variations observed in breast cancer incidence across countries can likely be at least partly attributed to differences in the prevalence and distribution of the major risk factors (e.g. reproductive factors, obesity) and partly to the degree of early detection and screening activities in operation. Breast cancer screening detects breast cancer at earlier stages, but also captures cases that would have never been diagnosed otherwise. As such, incidence rates are often higher in countries that implement breast cancer screening programs. In countries where the incidence of breast cancer is high, there has been a decline or stabilization of rates, while in countries where rates have historically been low, rates have been markedly increasing, probably related to improved diagnosis (i.e., detection of asymptomatic cancers) in combination with socio-cultural changes linked to an increase in westernized lifestyle. (Figure 3)
Figure 3. Female breast cancer incidence rates, all ages, 1978-2012. In the US, female breast cancer incidence rates among whites (age-standardized rate world per 100,000) increased from 73.6 in 1980 to a peak of 98 in 1999. It then declined to a plateau around 87 from 2005-2010. In the US, female breast cancer incidence rates among blacks (age-standardized rate world per 100,000) increased from 62.2 in 1980 to a plateau around 85 from 1997 to 2010. In Australia, female breast cancer incidence rates (age-standardized rate world per 100,000) increased from 80.4 in 1995 to 85.9 in 2010. In the UK, female breast cancer incidence rates (age-standardized rate world per 100,000) increased from 80.1 in 1997 to 87.4 in 2010. In Japan, female breast cancer incidence rates (age-standardized rate world per 100,000) increased from 37.5 in 2000 to 52.7 in 2008. In Turkey, female breast cancer incidence rates (age-standardized rate world per 100,000) increased from 36.9 in 2000 to 47.3 in 2010. In Ecuador, female breast cancer incidence rates (age-standardized rate world per 100,000) increased from 26.2 in 1987 to 38.5 in 2010. In Thailand, female breast cancer incidence rates (age-standardized rate world per 100,000) increased from 13.7 in 1995 to 25.5 in 2010.
Declines in breast cancer mortality rates have been reported in many high-income countries, with large decreases in European and North American countries and in Australia and New Zealand, whereas countries in transition continue to show a slight increase in mortality from breast cancer, though this appears to be slowing. (Figure 4) The favorable trends in mortality may result from the combined effects of earlier detection (screening and increased breast cancer awareness) and a range of improvements in treatment.
ACCESS CREATES PROGRESS
Although enormously challenging, resource stratified approaches to detect and treat breast cancers can substantially decrease breast cancer mortality worldwide.
Figure 4. Female breast cancer mortality rates, all ages, 1950-2013. In the UK, USA, and Australia, breast cancer mortality rates remained around 25 cases per 100,000 from 1950 to about 1990 before decreasing to around 15. In Japan, Thailand, and Ecuador, breast cancer mortality rates gradually increased from around 4 cases per 100,000 or less around 1950 to about 6 in 2010.
Access creates progress:
Lauby-Secretan B, Scoccianti C, Loomis D, et al. Breast-cancer screening – viewpoint of the IARC Working Group. New Engl J Med. 2015;372:2353–2358.
Text:
Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018; 68(6): 394–424.
Carioli G, Malvezzi M, Rodriguez T, Bertuccio P, Negri E, La Vecchia C. Trends and predictions to 2020 in breast cancer mortality in Europe. Breast. 2017; 36: 89–95.
Carioli G, Malvezzi M, Rodriguez T, Bertuccio P, Negri E, La Vecchia C. Trends and predictions to 2020 in breast cancer mortality: Americas and Australasia. Breast. 2018; 37: 163–9.
Torre LA, Islami F, Siegel RL, Ward EM, Jemal A. Global Cancer in Women: Burden and Trends. Cancer Epidemiol Biomarkers Prev. 2017; 26(4): 444–57.
Verdial FC, Etzioni R, Duggan C, Anderson BO. Demographic changes in breast cancer incidence, stage at diagnosis and age associated with population-based mammographic screening. J Surg Oncol. 2017; 115(5): 517–22.
Map and Figures 1 and 2:
Ferlay J, Ervik M, Lam F, et al. Global Cancer Observatory: Cancer Today. Lyon, France: IARC. Available from: https://gco.iarc.fr/today
Figure 3:
Five-year moving average.
Ferlay J, Colombet M and Bray F. Cancer Incidence in Five Continents, CI5plus: IARC CancerBase No. 9 [Internet]. Lyon, France: International Agency for Research on Cancer; 2018. Available from: http://ci5.iarc.fr.
Figure 4:
Five-year moving average.
World Health Organization Cancer Mortality Database, http://www-dep.iarc.fr/WHOdb/WHOdb.htm.