By Dr. Stefanie Trowell, ND
Since nearly half of young Canadian women are taking an oral contraceptive, and the number of intra-uterine devices (IUDs) being inserted continues to rise – wouldn’t you think it important for all of us to know a bit more about this topic? Just the other week I was speaking at a girls’ night (a sort of informal “ask the naturopathic doctor” get together) and the evening was dominated by questions about the birth control pill, IUDs and fertility awareness methods. Between the wine and delicious snacks, it became evident that the majority of women have little knowledge of what they are putting into their bodies when the alarm on their phone goes off at exactly the same time, every single day. And there is a lot to think about, but let’s start with something no one is talking about with regards to contraception – Breast Cancer risk.
Oral Contraceptives increase Breast Cancer Risk
Evidence for oral contraceptive use and increased breast cancer risk has been around for a number of years. Never heard about it? You are not the only one. It is not well advertised despite in 2005, the WHO raised the IARC classification of combined oral contraceptives to the highest category, which joins known carcinogens: arsenic, asbestos and tobacco smoke. I know what you are thinking – that tiny pill is equivalent to smoking cigarettes?!
So how can we be so blasé about a medication that increases the number one cancer affecting Canadian women (breast cancer) by up to 60%? Good question. Possibly because the effects are not instantly apparent and take time to come to fruition. One study found that girls who take the pill (for any length of time) before age 20 are at 3-4 times more likely to be diagnosed with breast cancer before the age of 50 (2). Or perhaps the message has been diluted by the emphasis on reduced teenage and unplanned pregnancies – or that the risk is only slightly above the population norm after stopping it for 10 years. Whatever the reason for the missed message, here a couple other fun facts about oral contraceptives that you may like to know:
- Oral contraceptives accelerate cell division and proliferation – a known mechanism for the development of cancer. Estrogen levels are 10-50 times higher in breast tissue than in the blood and are higher yet in cancerous tissues, making the breast an unplanned casualty.
- Combined contraceptives (“the pill” = estradiol + progestin) and Progestin-only contraceptives (the “mini-pill” = progestin) are equally carcinogenic.
- Levonorgestrel (a progestin), the sole ingredient of Plan B, is the equivalent of taking 40-50 oral contraceptives at once and was found to increase risk of breast cancer by 205%.
Hormonal IUDs increase Breast Cancer Risk
(*I couldn’t find any breast cancer risk information regarding copper IUDs, but it’s not a known risk factor). The story regarding hormonal IUD use and breast cancer has been controversial in the past and plagued with small sample sizes that yielded mixed results. Finally last year, a Finnish study provided some strong evidence that levonorgestrel-releasing intrauterine devices (i.e. hormonal IUDs) increased the risk of both ductal and lobular breast cancers in young women aged 30-49 years. The highest risk was found in women who had 2 or more devices inserted; the incidence of lobular breast cancer in that population was 73% greater than their non-user cohorts (6). I find this information especially concerning as there has been a noticeable increase in IUDs being recommended by family practitioners. Combine this with the increasing trend for young women (aged 49 and less) to be diagnosed with breast cancer and BRCA gene mutations, and the faces of women fighting breast cancer may start to look even younger.
So what is a young woman to do?
Receiving counselling around fertility awareness and making a plan for coming off your contraceptive is a big step. You may not be ready for that just yet, but there are ways that we can work together to reduce the impact of the contraceptive on your health. If you feel that are ready to find a balance of pleasures today and future health investment, come see me at Darou Wellness or grab a couple of girlfriends and we’ll plan for a girls’ night all of your own!
- Beaber, Elisabeth F., et al. “Oral contraceptives and breast cancer risk overall and by molecular subtype among young women.” Cancer Epidemiology Biomarkers & Prevention 23.5 (2014): 755-764.
- Black, A. Yang, Q., Wen, S.W. et al. (2009). Contraceptive use among Canadian women of reproductive age: Results of a national survey. Journal of Obstetrics and Gynaecology Canada, July, 627-640. http://www.sexualityandu.ca/professionals/pdfs/National%20Contraception%20Survey.pdf
- Huzell, Louise, et al. “History of oral contraceptive use in breast cancer patients and risk for early breast cancer events.” Cancer Research 75.15 Supplement (2015): 855-855.
- Li, Christopher I., et al. “Effect of depo-medroxyprogesterone acetate on breast cancer risk among women 20 to 44 years of age.” Cancer research 72.8 (2012): 2028-2035.
- Schneider, A. Patrick, et al. “The breast cancer epidemic: 10 facts.” The Linacre Quarterly 81.3 (2014): 244-277.
- Soini, Tuuli, et al. “Levonorgestrel-releasing intrauterine system and the risk of breast cancer: A nationwide cohort study.” Acta Oncologica (2015): 1-5.