Milan, Italy—Widespread use of oral contraceptives is pushing down deaths caused by ovarian cancer, according to a new study.
The report, published in Annals of Oncology, notes that deaths from ovarian cancer fell worldwide between 2002 and 2012. The decline is predicted to continue in the United States, Europe and, to a lesser degree, Japan until 2020.
University of Milan–led researchers posit that the main reason for lower mortality rates is the use of oral contraceptives, which provide long-term protection against ovarian cancer. Also appearing to play a part were the decline in hormone replacement therapy (HRT) usage to manage menopausal symptoms, as well as better diagnosis and treatment, according to study authors.
Employing World Health Organization data on deaths from ovarian cancer from 1970 to the most recent available year, the study indicates that, in the 28 countries of the European Union (minus Cyprus due to the unavailability of data), death rates decreased by 10% between 2002 and 2012, from an age-standardized death rate per 100,000 women of 5.76 to 5.19.
In the U.S., meanwhile, the decline was much greater, with a 16% drop in death rates from 5.76 per 100,000 in 2002 to 4.85 in 2012. The drop in death rates was nearly 8% in Canada, about 12% in Australia and New Zealand and 22% in Britain, results indicate.
In Japan, which has had a lower rate of ovarian cancer deaths than many other countries, the death rate fell by 2% from 3.3 to 3.28 per 100,000.
The report points out, however, that the pattern of decreases was inconsistent in some areas of the world. In Europe, for example, the percentage decrease ranged from 0.6% in Hungary to more than 28% in Estonia, while Bulgaria was the only European country to show an apparent increase. Other large decreases were in Austria (18%), Denmark (24%), and Sweden (24%).
“The large variations in death rates between European countries have reduced since the 1990s when there was a threefold variation across Europe from 3.6 per 100,000 in Portugal to 9.3 in Denmark,” noted lead researcher Carlo La Vecchia, MD. “This is likely to be due to more uniform use of oral contraceptives across the continent, as well as reproductive factors, such as how many children a woman has.”
La Vecchia added, however, that “there are still noticeable differences between countries such as Britain, Sweden and Denmark, where more women started to take oral contraceptives earlier—from the 1960s onwards—and countries in Eastern Europe, but also in some other Western and Southern European countries such as Spain, Italy, and Greece, where oral contraceptive use started much later and was less widespread.”
In the U.S., he said, oral contraceptives tended to be used earlier but, in Japan, where deaths from ovarian cancer have traditionally been low, “younger women have higher rates reflecting infrequent oral contraceptive use."
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