Breast Cancer Incidence Increasing in Underdeveloped Countries

Economic development and urbanization factors influence cancer incidence growth.

The incidence of breast cancer is increasing in economically developing countries around the world, even as death rates have declined in most high income countries. The findings were published in a new report that appears online in Cancer Epidemiology Biomarkers and Prevention.

Breast cancer is the most commonly diagnosed cancer among all women and is the leading cause of cancer-related death in women globally. While it was once considered a disease for Western women, 52% of new breast cancer cases and 62% of deaths now occur in economically developing countries.

Researchers examined trends in incidence and death rates at an international level from 39 and 57 countries, respectively. They found that breast cancer incidence rates are increasing in most countries, including those with historically higher rates, such as those in Europe, as well as in many countries in Latin America, Asia, and Africa where rates have been historically lower.

In North America incidence rates have been stabilized, with incidence rates declining in 4 European countries, as well as Israel.

Contrarily, death rates have decreased in most countries. The decreasing trends appear most in high income countries as a result of improved breast cancer treatment and early detection through mammography.

However, death rates have increased in 10 countries including Colombia, Ecuador, Japan, Brazil, Egypt, Guatemala, Kuwait, Mauritius, Mexico, and Moldova.

“Mortality rates are decreasing in most high income countries, even as incidence rates are increasing or stable,” said lead researcher Carol E. DeSantis, MPH, a senior epidemiologist for the American Cancer Society. “That’s the good news. But of real concern are increasing incidence and mortality rates in a number of countries, particularly those undergoing rapid changes in human development.”

The increase in breast cancer incidence in developing countries is likely due to an increase in risk factors associated with economic development and urbanization, including obesity; adaptation of a Western-type diet; physical inactivity; delayed childbearing; having fewer children; earlier age at menarche; and shorter duration of breastfeeding.

“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,” the study concluded.