A study has said newer versions of birth control pills pose as much risk of breast cancer as earlier ones that were discarded in the 1990s.
The study was published in the New England Journal of Medicine.
The researchers tracked about 1.8 million women from 1995 through 2012 to see whether the lower amounts of estrogen helped reduce or eliminate the added breast cancer risk.
The study found that women taking modern formulations of the pill have a 20 percent increased risk of breast cancer compared with those who have never been on hormonal contraception.
“The risk increases with increasing duration of use and persists for more than five years, if used for longer than five years,” said study author Lina Morch, a senior epidemiologist with the University of Copenhagen, Denmark.
Morch, however, said breast cancer is relatively uncommon in younger women, so a young woman’s overall risk of breast cancer still is low, even if she’s taking the pill.
The researchers also discovered an increased breast cancer risk in birth control pills that only contain progestin.
“Progestin-only products also increased the risk of breast cancer,” Morch said. “Thus, it is not exclusively estrogen that increases the risk of breast cancer.”