In her recent doctoral dissertation, researcher Sanna Heikkinen from the University of Helsinki and Finnish Cancer Registry evaluates the contribution of the use of hormonal contraceptives and hair dyes to the spectrum of breast cancer risk factors.
The analysis included self-reported survey data from 8000 breast cancer patients and 20,000 controls from Finland.
According to the results, use of hormonal intrauterine device was associated with 52% increased risk of breast cancer in post-menopausal women, when compared to women who had used copper intrauterine device.
The use of other hormonal contraceptives was, by contrast, associated with 32% higher breast cancer risk among younger women under 50 when compared to women who did not use hormonal contraceptives.
There was also a 23% observed increase in the risk of breast cancer among women who dyed their hair compared to those who didn’t.
Dr. Stegall’s Comments: As hormonally-based birth control has become commonplace, little consideration has been given to the long-term effects of synthetic hormones. With hormonal-based contraceptives, we are giving additional hormones on top of what the body normally produces, in an effort to trick the body into thinking it is already pregnant. If the body thinks it is pregnant, it will not release an egg with the monthly cycle for potential fertilization. While it sounds like a great way to prevent pregnancy, the study above – as well as others – have shown that there is a trade-off. Unfortunately, that trade-off appears to be an increased risk for cancer later in life.
I feel strongly that we need to think carefully about the casual use of hormone-based birth control in our society. The decision to use a hormonal-based contraceptive should be a careful one, with the pros and cons weighed in a thoughtful manner.