CHICAGO (AP) Modern birth control pills that are lower in estrogen have fewer side effects than past oral contraceptives.
But a large Danish study suggests that, like older pills, they still modestly raise the risk of breast cancer, especially with long-term use.
Researchers found a similar breast cancer risk with the progestin-only intrauterine device.
The overall increased risk was small. It amounted to one extra case of breast cancer among 7,700 women using hormone contraceptives per year.
Experts say women should balance the news against known benefits of the pill - including lowering the risk of other cancers.
The study is based on health records of 1.8 million women in Denmark.
Results were published Wednesday in the New England Journal of Medicine.