Key clinical point: Current or recent use of either progestagen-only or oral estrogen+progestagen contraceptives increased the risk for breast cancer (BC) by 20%-30% in premenopausal women aged <50 years.
Major finding: Risk for incident BC was significantly increased in women who used vs did not use oral estrogen+progestagen (adjusted odds ratio [aOR] 1.23; P < .001), oral progestagen (aOR 1.26; P < .001), injectable progestagens (aOR 1.25; P = .004), or progestagen intra-uterine devices (aOR 1.32; P < .001).
Study details: Findings are from a nested case-control study including 9498 premenopausal women aged <50 years with BC and 18,171 matched control individuals and a meta-analysis including 12 observational studies for progestagen-only preparations.
Disclosures: This study was supported by the Cancer Epidemiology Unit by Cancer Research UK and UK Medical Research Council. The authors declared no conflicts of interest.
Source: Fitzpatrick D et al. Combined and progestagen-only hormonal contraceptives and breast cancer risk: A UK nested case–control study and meta-analysis. PLoS Med. 2023;20(3):e1004188 (Mar 21). Doi: 10.1371/journal.pmed.1004188