En meta- analyse af 54 epidemiologiske studier rapporterede, at der er en let forøget risiko (RR = 1, 24) for at få brystcancer diagnosticeret hos kvinder, der aktuelt anvender COC' er.
7 A meta-analysis of 54 epidemiological studies reported that there is a slightly increased risk (RR = 1.24) of having breast cancer diagnosed in women who are currently using COCs.