Case-Control-Study on the Breast Cancer Risk of Mirena® Compared With Copper IUDs

This is a community-based case-control study in Germany and Finland. Cases will be identified from cancer registries, tumor centers and breast centers. Matched controls will be accrued from the same region as the case came from. Breast cancer cases and their controls are women under 50 years of age without known history of malignancies.

Cases are women with a breast cancer who are younger than 50 years of age at cancer diagnosis. The breast cancer was diagnosed between January 2000 and December 2007. Only alive cases and cases in a sufficiently good health status to be interviewed are eligible for the study.

Controls are women without a breast cancer diagnosis who are younger than 50 years of age at the time of the interview. About 3 controls matched by year of birth and region will be allocated to each case.

A standardized questionnaire will be used for all breast cancer cases and controls. The questionnaire will be mailed to cases and controls.

Study participants will be asked for their informed consent. Data confidentiality according to national laws will be ensured by the field organizations.

• Levonorgestrel-releasing IUD (Device), also known as Mirena: This is a case-control-study; strictly speaking the category "intervention type" does not apply to this study.
• Copper IUD (Device): This is a case-control-study; strictly speaking the category "intervention type" does not apply to this study.

Primary outcomes

• Breast Cancer Risk [retrospective, January 2000 to December 2007]: Breast cancer (invasive carcinoma or carcinoma in situ) in women aged <50 years at diagnosis. Cases were excluded if they had died before study start or had a history of malignancy.

Sex: Female, ages: any to 50 Years, accepts healthy volunteers

Inclusion Criteria:

* cases: women with a breast cancer who are younger than 50 years of age at cancer diagnosis
* controls: women without a breast cancer diagnosis who are younger than 50 years at the time of the interview

Exclusion Criteria:

* women who are not willing to participate

Participant flow

Outcome results

• Breast Cancer Risk (Primary), Number, participants: LNG IUD 1076; Cu-IUD 1068

Adverse events

Time frame: Retrospective population based case-control study identifying breast cancer cases in the between January 2000 and December 2007 in women younger than 50 years of age at time of diagnosis.

Serious adverse events by term

Limitations and caveats: Limitations include information-bias, which cannot be entirely eliminated in retrospective studies. However, in this study recall is likely not to be differential between cases and controls.

• Results publication: Dinger J, Bardenheuer K, Minh TD. Levonorgestrel-releasing and copper intrauterine devices and the risk of breast cancer. Contraception. 2011 Mar;83(3):211-7. doi: 10.1016/j.contraception.2010.11.009. Epub 2011 Jan 7. PMID 21310281

• Juergen Dinger, MD, PhD, Principal investigator, Center for Epidemiology and Health Research