Despite the widespread use of the oral contraceptive pill, uncertainty still exists over its association with cancer.
Researchers from the University of Aberdeen analysed data from the Royal College of General Practitioners’ oral contraception study involving 46,022 UK women who have been followed for up to 44 years; the longest running study on the effects of oral contraception.
The team found that “ever” use of oral contraceptives was associated with a reduced risk of colorectal (incidence rate ratio [IRR] 0.81), ovarian (IRR 0.67), endometrial (IRR 0.66) and lymphatic and haematopoietic cancer (IRR 0.74). An increased risk of breast and cervical cancer seen in current and recent users did not persist beyond five years of stopping.
Reporting in the American Journal of Obstetrics and Gynecology
(online, 8 February 2017), the team says that women who use oral contraceptives do not expose themselves to long-term cancer risk and may receive some protection.
 Iversen L, Sivasubramaniam S, Lee AJ et al. Lifetime cancer risk and combined oral contraceptives: the Royal College of General Practitioners’ oral contraception study. Am J Obstet Gynecol 2017; doi: 10.1016/j.ajog.2017.02.002