Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT05972785 |
| Other study ID # |
2014896 |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
July 1, 2022 |
| Est. completion date |
December 2025 |
Study information
| Verified date |
August 2023 |
| Source |
Curtin University |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
The goal of this retrospective observational study is to examine whether long-term calcium
channel blocker (CCB) use is associated with the development of breast cancer amongst women
enrolled in three longitudinal cohort studies in Australia and the Netherlands . The main
questions it aims to answer are:
- Is long-term CCB use associated with the development of breast cancer amongst women
enrolled in three longitudinal cohort studies in Australia and the Netherlands and what
is the dose-response nature of this association.
- Does differences in the association between calcium channel blocker use and the
development of breast cancer exist between Australian and Dutch women.
The investigators will utilise data from the Australian Longitudinal Study on Women's Health
(ALSWH) , 45 and Up Study and Rotterdam study.
Description:
Aims: To examine the association between long-term calcium channel blocker (CCB) use and the
development of breast cancer.
Data sources: the Australian Longitudinal Study on Women's Health , 45 and Up Study,
Rotterdam study and linked administrative data.
Study cohort: Women with self-reported hypertension (HTN) without prior breast cancer.
Harmonisation: Relevant variables will be checked for harmonisation in which variables
available in all three cohort will be used in the harmonised analysis. The variables will be
checked on the definition, measurement and harmonisation rules. Variables that cannot be
harmonised across the cohorts will be used in the cohort specific analyses.
Exposure measurement: The primary exposure is the use of CCB, which will be identified by the
anatomical therapeutic chemical code (C08) in the medicine data. Exposure to CCB as well as
other antihypertensive (AHT) medicines will be captured separately as the cumulative
dose-duration of exposure during follow up. Participants will be stratified in four groups:
women with HTN with no AHT use, women with HTN exposed to CCB only, women with HTN exposed to
non-CCB and women with HTN exposed to both CCB and non-CCB.
Outcome measurement: Data on a diagnosis of invasive breast cancer will be obtained from
cancer registries and hospital admission data using ICD-10 code of C50.x.
Potential confounders: age, education, marital status, socioeconomic status, body mass index,
diabetes, heart disease, stroke, age when had first child, parity, history of hysterectomy or
oophorectomy, use of hormonal contraception, use of hormonal replacement therapy.
Statistical analysis: The association between CCB use and breast cancer risk will be
estimated by the Fine and Gray competing risk regression model in which a first diagnosis of
invasive breast cancer will be treated as the principle event and death and bilateral
mastectomy (without a diagnosis of breast cancer) will be competing risks. The nonlinear
threshold models will be used to capture any differential effect of the cumulative
dose-duration of CCB while simultaneously accounting for the cumulative dose-duration of
other AHT exposure on breast cancer risk. Other confounders will be accounted for in the
models using propensity scores.
Implications: Results from this study will contribute to addressing the concerns about using
CCB for hypertension treatment in women, particularly in those who have high risk of breast
cancer.
