Breast Cancer
Conditions
Keywords
breast cancer
Brief summary
The objective of this study is to determine the breast cancer risk of Mirena® users compared to copper intrauterine device (IUD) users in a community-based case-control study.
Detailed description
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.
Interventions
DEVICELevonorgestrel-releasing IUD
This is a case-control-study; strictly speaking the category intervention type does not apply to this study.
DEVICECopper IUD
This is a case-control-study; strictly speaking the category intervention type does not apply to this study.
Sponsors
Bayer
Center for Epidemiology and Health Research, Germany
Study design
Observational model
CASE_CONTROL
Eligibility
Sex/Gender
FEMALE
Age
No minimum to 50 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
Germany
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Cases Cases were defined as women who were diagnosed with breast cancer (invasive carcinoma or carcinoma in situ) between 1/2000 and 12/2007 and aged \<50 years at diagnosis. | 5,113 |
| Controls Controls were selected randomly from the national population registry (Finland) or via neighborhood controls by a controlled random route method (Germany). | 20,452 |
| Total | 25,565 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | administrative | 773 | 7,773 |
| Overall Study | Death | 985 | 0 |
| Overall Study | no response | 2,609 | 11,789 |
| Overall Study | Protocol Violation | 613 | 236 |
Baseline characteristics
| Characteristic | Controls | Cases | Total |
|---|---|---|---|
| Age, Continuous | 44.2 years STANDARD_DEVIATION 5.1 | 44.5 years STANDARD_DEVIATION 5.1 | 44.3 years STANDARD_DEVIATION 5.1 |
| Gender Female | 20,452 participants | 5,113 participants | 25565 participants |
| Gender Male | 0 participants | 0 participants | 0 participants |
| Region of Enrollment Finland | 13192 participants | 3298 participants | 16490 participants |
| Region of Enrollment Germany | 7260 participants | 1815 participants | 9075 participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 5,346 | 0 / 5,428 |
| serious Total, serious adverse events | 1,085 / 5,346 | 1,130 / 5,428 |
Outcome results
Primary
Breast Cancer Risk
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.
Time frame: retrospective, January 2000 to December 2007
Population: Frequency of breast cancer (in situ and invasive) in LNG-IUD users and Cu-IUD users
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| LNG IUD | Breast Cancer Risk | 1076 participants |
| Cu-IUD | Breast Cancer Risk | 1068 participants |
Comparison: In this matched case-control study, conditional logistic regression was used to investigate the relationship between a woman being a breast cancer case or a control (dichotomous dependent variable), and a set of actual or potential prognostic factors (covariates) for breast cancer (incl. the use of Mirena). Conditional logistic regression uses a maximum likelihood approach for estimating the covariates; data are stratified and the likelihoods are computed relative to each stratum.95% CI: [0.88, 1.12]
Comparison: In this matched case-control study, conditional logistic regression was used to investigate the relationship between a woman being a breast cancer case or a control (dichotomous dependent variable), and a set of actual or potential prognostic factors (covariates) for breast cancer (incl. the use of Mirena). Conditional logistic regression uses a maximum likelihood approach for estimating the covariates; data are stratified and the likelihoods are computed relative to each stratum.95% CI: [0.93, 1.17]
Comparison: In this matched case-control study, conditional logistic regression was used to investigate the relationship between a woman being a breast cancer case or a control (dichotomous dependent variable), and a set of actual or potential prognostic factors (covariates) for breast cancer (incl. the use of Mirena). Conditional logistic regression uses a maximum likelihood approach for estimating the covariates; data are stratified and the likelihoods are computed relative to each stratum.95% CI: [0.52, 1.39]
Comparison: In this matched case-control study, conditional logistic regression was used to investigate the relationship between a woman being a breast cancer case or a control (dichotomous dependent variable), and a set of actual or potential prognostic factors (covariates) for breast cancer (incl. the use of Mirena). Conditional logistic regression uses a maximum likelihood approach for estimating the covariates; data are stratified and the likelihoods are computed relative to each stratum.95% CI: [0.58, 1.41]