CINCINNATI (WKRC) – A study of more than 2 million women found a “statistically significant” association between hormonal contraceptive use and an increased risk of breast cancer. published in JAMA Oncology.
Studies have shown that women who use birth control pills that contain only one hormone, a type of progesterone called desogestrel, have a 21 percent higher risk of developing breast cancer. People who took a combination pill containing both estrogen and progesterone had a 12% increased risk.
The researchers said the link with desogestrel was a new finding that had not been previously documented. They suggested that the estrogen in the combination pill may offset some of the harmful effects of the progestin, slightly lowering the risk.
Despite the findings, the study authors urged caution in interpreting them, noting that the overall benefits of hormonal contraceptives, including preventing unintended pregnancy and reducing the risk of ovarian and endometrial cancer, remain significant. They emphasized the importance of individualized counseling between patients and health care providers.
According to the Cleveland Clinic, Progestin-only pills, or “minipills,” prevent pregnancy by thickening cervical mucus, preventing ovulation, and thinning the uterine lining. Combination medications use both hormones to achieve the same effect and typically include three weeks of active medication and one week of inactive medication or a placebo medication.
Researchers said more research is needed to understand how different hormonal contraceptives affect breast cancer risk.
