According to a study by researchers at the International Prevention Research Institute in Lyon, France, breast cancer death rates in the United States have dropped by 42% from 1987 to 2013. Still, death rates in South Korea and some Latin American countries saw death rates from the disease increase.
The research, "Overview of breast cancer mortality trends in the world," was presented on Dec. 9, 2016 at the 2016 San Antonio Breast Cancer Symposium.
To do the study, the researchers analyzed information in the World Health Organization database.
Overall, death rates from breast cancer declined in 39 out of 47 countries for which there was data, including the United States and most European countries. England and Wales had the largest drop in breast cancer death rates: 46%. The researchers said this trend was to be expected, given the advances in detection and treatment in the last few decades.
One limitation of the study was a lack of information on breast cancer deaths in many Latin American, Asian, and African nations.
In Latin America, death rates declined in some countries and went up in others:
- Brazil and Colombia saw breast cancer death rates increase in women of all age groups.
- In Argentina and Chile, death rates went down among women of all ages.
South Korea had the highest increase in breast cancer death rates: 83% overall and higher death rates in women of all age groups. Still, this rate continues to be lower than the breast cancer death rate in the United States. From 2011 to 2013, there were:
- 5.3 deaths from breast cancer per 100,000 women in South Korea
- 14 deaths from breast cancer per 100,000 women in the United States
"South Korea has experienced major societal changes since the 1950s and quickly evolved from an agricultural, developing country to a highly industrialized and Westernized country," said the study’s lead author Cécile Pizot. "Such quick changes might explain the considerable shift in cancer mortality."
Other highlights of the study:
- In the United States, the breast cancer death rate declined 42%, from 22 deaths per 100,000 women in 1987-1989 to 14 deaths per 100,000 women in 2011-2013. Pizot said mortality rates declined for all age groups -- by 50% for women younger than 50, by 44% for women between 50 and 69 years old, and by 31% for women 70 or older.
- Globally, mortality rates declined more for women younger than 50 than for women older than 50. Pizot said this reflects the fact that younger women tend to receive more intensive treatments, which can improve survival.
- Pizot said the role of breast cancer screening is not clearly apparent in breast cancer death rate trends. She said the study revealed several cases where nations with similar geographic locations and socioeconomic statuses experienced similar trends, no matter whether the country has used mammography screening since the 1980s or whether mammography was introduced in 2005 or later.
"This finding underlines the difficulty of isolating a single, common factor that would have a major influence on mortality trends," Pizot said, adding that future research on breast cancer mortality should focus on other facets of breast cancer management, including risk factors, drug therapies, access to care, and the use of multidisciplinary teams.
"Differences in healthcare systems and patient management could explain discrepancies in mortality reduction between similar countries," Pizot said. "However, there is at present little data comparing the management of breast cancer patients across countries."