Low- and middle-income countries are seeing a rise in breast cancer incidence and death rates, despite the fact that death rates have decreased in higher-income countries, where incidence rates have increased or stabilized, according to a new study published in Cancer Epidemiology, Biomarkers and Prevention.
Although breast cancer was once considered to be primarily a disease of Western women, 52% of new cases and 62% of deaths now occur in economically developing countries, wrote the group led by Carol DeSantis of the American Cancer Society (ACS).
DeSantis and colleagues used incidence data for 39 countries from the International Agency for Research on Cancer (IARC) and mortality data for 57 countries from the World Health Organization (WHO) to assess international trends (Cancer Epidemiol Biomarkers Prev, September 10, 2015).
They found that breast cancer incidence rates are increasing in most countries, including those with historically higher rates, such as Europe, as well as in many countries in Latin America, Asia, and Africa -- regions with historically lower incidence rates. Incidence rates are stable in North America and Oceania and have declined in four European countries and Israel.
The researchers suggest that the uptick in breast cancer incidence in developing countries may be due to an increase in risk factors associated with economic development and urbanization, such as obesity, adoption of a Western-type diet, physical inactivity, delayed childbearing and having fewer children, earlier age at menarche, and shorter duration of breastfeeding.
In contrast to incidence rates, breast cancer death rates have decreased in most countries, especially high-income ones, due to improved breast cancer treatment and early detection through mammography, the group wrote. However, 10 countries are the exception to this rule: Colombia, Ecuador, Japan, Brazil, Egypt, Guatemala, Kuwait, Mauritius, Mexico, and Moldova.
"It is necessary to increase awareness about breast cancer and the benefits of early detection, most notably in economically transitioning countries, in order to successfully implement breast cancer control programs, as well as to improve access to treatment," DeSantis and colleagues concluded.
