Hormonal Contraceptives may Increase a Woman’s Risk of Breast Cancer
By Ramadhani Chambuso
The risk of breast cancer was elevated among women who used hormonal contraceptives than among women who had never used them before, a study suggests, published in December, 2017 on the top journal in human Medicine, New England Journal of Medicine.
The study was done in Denmark, followed up 1.8 million women for 10.9 years who used hormonal birth control methods and only 11,517 cases of breast cancer occurred. Furthermore, when compared with women who have never used any hormonal control pills, the risk of breast cancer increased up to 38% depending on duration of use from less than 1 year to more than 10 years in all forms of hormonal contraception methods such as the pills, injections or hormone releasing-Intra Uterine Devices (IUDs).
However, the overall absolute increased risk in breast cancers diagnosed among current and recent users of any hormonal contraceptive was 13%, approximately 1 extra breast cancer for every 7690 women using hormonal contraception for 1 year.
Although these findings sound scary, on the other hand, the risk is somehow similar to the breast cancer risk contributed by physical inactivity, excessive weight gain, or alcohol consumption. However, all these extra contributing factors for breast cancer risk were not excluded in this study.
In contrary, oral contraceptives use, prevents more cancers than it causes. For example, it is known to reduce the risk of ovarian cancer, endometrial cancer and there is a strong suggestion that they may also reduce the risk of colorectal cancer.
In my opinion, this should be weighed against the clear benefits of hormonal contraception use that go beyond the obvious advantages of preventing unwanted pregnancies. In addition, the search for new hormonal contraceptives that do not elevate breast cancer risk or use of copper IUDs should be alternatively emphasized.
Source: Mørch et al. (2017).
Hormonal contraception (and not IUD) has also been shown to reduce the risk of bacterial vaginosis (BV), the most common form of vaginal disorder among reproductive-age women. The benefits of hormonal contraception are also seen in women with HPV infections. In a population-based, 5-year longitudinal study to assess the determinants of HPV clearance in 227 HPV-positive Colombian women aged 13-85 years with normal cytology, Molano (2003) observed that 23% and 7% of HPV infections still persisted after 1 year and 5 years, respectively. Women who had ever used oral contraceptives had faster clearance rates than their counterparts. Peristent HPV is a prerequisite for the development of cervical intraepithelial neoplasia (CIN) and cervical cancer. Recently, we showed that hormonal contraceptive is associated with increased abundances of vaginal Lactobacillus, which may be protective against BV. BV may play a role in the progression of CIN and cervical cancer. With these findings, I would second you when it comes evaluating the future applicability of contraceptives.
Thanks for the valuable information Harris, as well this should be a blog post on it’s own… I suggest. It’s really a new information to me… thanks again.
If we manage to publish part of my research findings next year, then I will blog it. Welcome.