Oral contraception is reported to be a highly effective method of birth control and is used globally. However, a recent study looked at the risk of breast cancer associated with the use of Combined oral contraceptives (COCs) and progesterone-only contraception (POC).
COCs containing both estrogen and progesterone are prescribed in most circumstances, rather than the progesterone-only option. Earlier studies have shown that using COCs can be associated with a slight increase in breast cancer risk. However, that risk is alleviated a decade following cessation of use. POP use is rising, but not much is known about this risk due to the low prevalence of use hitherto.
The data used in this study was obtained from the Clinical Practice Research Datalink (CPRD), a UK database acquired from primary care practitioners.
The scientists compared the presence of prescriptions for hormonal contraceptives in approximately 9,500 women under 50 years who developed invasive breast cancer between 1996 and 2017, with over 18,000 controls. All cases and controls had clinical data available for a mean of seven years prior to the diagnosis of cancer.
Over three-quarters of the cases were in women between 40 and 49, with a fifth being in those aged 30-39 years and only 2% in those under 30 years.
The results from this database were amalgamated with those of earlier studies on POC from January 1995 to November 2022. This was done to arrive at a stronger association, if present, given the paucity of data in any single study.
