The research also suggests that the hormone progestin — widely used in today’s birth control methods — may be raising breast cancer risk. The study was limited, the authors said, because they could not take into account factors like physical activity, breast feeding and alcohol consumption, which may also influence breast cancer risk. Among those who used hormones for five years, an increased breast cancer risk persisted even after they discontinued use, Dr. Mørch said. But by the time a woman reaches 40, her probability of developing breast cancer in the next 10 years is 1.45 percent, or 1 in 69. By contrast, there was no increased risk for breast cancer seen in women who used hormones for less than one year.

Source: New York Times December 06, 2017 22:12 UTC