WEDNESDAY, Sept. 7, 2016 (HealthDay News) -- Ovarian cancer deaths are down dramatically in many parts of the world, and researchers believe the use of birth control pills may be a main reason why.
The analysis of World Health Organization data found that the ovarian cancer death rate fell 16 percent in the United States and almost 8 percent in Canada between 2002 and 2012.
In the European Union, the ovarian cancer death rate fell 10 percent, though some countries saw far more significant drops. The United Kingdom's ovarian cancer death rate went down by 22 percent. Denmark and Sweden each saw a drop of 24 percent in their death rate from ovarian cancer, the researchers said.
Ovarian cancer deaths also decreased about 12 percent in both Australia and New Zealand. In Japan, the ovarian cancer death rate declined 2 percent, the study found. Japan has low rates of birth control use, the researchers said.
Ovarian cancer death rates are expected to continue to decline 15 percent in the United States, and 10 percent in the European Union and Japan by 2020.
In Latin America, the results were mixed. Argentina, Chile and Uruguay had decreases in ovarian cancer death rates between 2002 and 2012. But, Brazil, Colombia, Cuba, Mexico and Venezuela all had increases, according to the study.
The study was published Sept. 6 in the journal Annals of Oncology.
The study wasn't designed to prove cause-and-effect. However, a big reason for the decline in ovarian cancer death rates in some parts of the world is likely the use of birth control pills and the long-term protection against ovarian cancer they provide, study leader Dr. Carlo La Vecchia, a professor in the Faculty of Medicine at the University of Milan, Italy, and colleagues, suggested.
Other factors may include reduced use of hormone replacement therapy to manage menopausal symptoms and better diagnosis and treatment of ovarian cancer, the researchers said.
"As our understanding of preventable causes of this major cancer progresses, early detection strategies are being developed and novel therapeutic options become available, we enhance our ability to reduce ovarian cancer mortality," Dr. Paolo Boffetta, the journal's associate editor, wrote in an accompanying editorial. Boffetta is also director of the Institute of Translational Epidemiology at the Icahn School of Medicine at Mount Sinai in New York City.
The American Cancer Society has more on ovarian cancer.