It is very difficult to conclusively state whether the oral contraceptive pill directly impacts cancer rates; not least because the time between taking the pill and receiving a positive cancer diagnosis can span many years, during which time a female may be exposed to multiple (additional) risk factors.
What is becoming apparent is that different cancer types have differing risk/benefit profiles when it comes to an association with the pill. Whilst pill use seems to lower the risk of developing certain cancers, there is a more negative link with other types, including cervical cancer.
Taking the pill for five or more years is associated with a significantly increased risk of developing cervical cancer. The duration of use increases the risk, so that women who take the pill for 5 years have a 10% increased risk, but those who take it for longer, are more than 60% more likely to be diagnosed. Ten years after stopping the pill there is no increased risk of developing cervical cancer.
Cervical cancer and HPV
One important thing to note is that as a risk, oral contraceptives will always be cofactors that interact with high risk human papillomavirus (HPV) strains to induce cervical carcinogenesis. This means that oral contraceptives in isolation are not a risk factor in women who are HPV negative; however, for those who are HPV positive, the pill can exacerbate the risk. Steroid hormone receptors (mainly progesterone) are found in cervical tissue and are thought to enhance the expression of high risk HPV, contributing to cancerous changes in the cervix.
Take home message
The link between pill use and cervical cancer is really only realised in those women who test positive for HPV. Reducing your risk of contracting HPV, via vaccination, or identifying pre-cancerous changes early on, via PAP screening, are more effective methods of minimising cervical cancer risk.
To read more about a possible link between pill use and cancer risk click here.
Nabta is reshaping women’s healthcare. We support women with their personal health journeys, from everyday wellbeing to the uniquely female experiences of fertility, pregnancy, and menopause.
Get in touch if you have any questions about this article or any aspect of women’s health. We’re here for you.
- Brynhildsen, Jan. “Combined Hormonal Contraceptives: Prescribing Patterns, Compliance, and Benefits versus Risks.” Therapeutic Advances in Drug Safety, vol. 5, no. 5, Oct. 2014, pp. 201–213., doi:10.1177/2042098614548857.
- “Does the Contraceptive Pill Increase Cancer Risk?” Cancer Research UK, 4 Mar. 2019, https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/hormones-and-cancer/does-the-contraceptive-pill-increase-cancer-risk.
- Gierisch, J. M., et al. “Oral Contraceptive Use and Risk of Breast, Cervical, Colorectal, and Endometrial Cancers: A Systematic Review.” Cancer Epidemiology Biomarkers & Prevention, vol. 22, no. 11, Nov. 2013, pp. 1931–1943., doi:10.1158/1055-9965.epi-13-0298.
- Knowlden, Hilary A. “The Pill and Cancer: a Review of the Literature. A Case of Swings and Roundabouts?” Journal of Advanced Nursing, vol. 15, no. 9, Sept. 1990, pp. 1016–1020., doi:10.1111/j.1365-2648.1990.tb01981.x.
- “Oral Contraceptives (Birth Control Pills) and Cancer Risk.” National Cancer Institute, https://www.cancer.gov/about-cancer/causes-prevention/risk/hormones/oral-contraceptives-fact-sheet.
- Roura, Esther, et al. “The Influence of Hormonal Factors on the Risk of Developing Cervical Cancer and Pre-Cancer: Results from the EPIC Cohort.” Plos One, vol. 11, no. 1, 25 Jan. 2016, doi:10.1371/journal.pone.0147029.
- Smith, Jennifer S, et al. “Cervical Cancer and Use of Hormonal Contraceptives: a Systematic Review.” The Lancet, vol. 361, no. 9364, 5 Apr. 2003, pp. 1159–1167., doi:10.1016/s0140-6736(03)12949-2.