A nested case–control study in the Clinical Practice Research Datalink (CPRD), including almost 10,000 women aged <50 years with breast cancer, to assess the relationship between a woman’s recent use of hormonal contraceptives and her subsequent risk of breast cancer.
Results suggest that current or recent use of hormonal contraceptives was associated with a similarly increased risk of breast cancer of around 20% to 30% regardless of whether the preparation last used was oral combined, oral progestagen-only, injectable progestagen, progestagen implant, or progestagen intrauterine device.
Combining the findings for oral contraceptives with results from previous studies (which included women in a wider age range), the 15-year absolute excess risk of breast cancer associated with use of oral contraceptives ranges from 8 per 100,000 users (an increase in incidence from 0.084% to 0.093%) for use from age 16 to 20 to about 265 per 100,000 users (from 2.0% to 2.2%) for use from age 35 to 39.
These excess risks must be viewed in the context of the well-established benefits of contraceptive use in women’s reproductive years.
Source: PLOS Medicine