Study type

Study type

Non-interventional study

Scope of the study

Disease epidemiology
Drug utilisation
Effectiveness study (incl. comparative)
Non-interventional study

Non-interventional study design

Cohort
Study drug and medical condition

Anatomical Therapeutic Chemical (ATC) code

(L01D) CYTOTOXIC ANTIBIOTICS AND RELATED SUBSTANCES
CYTOTOXIC ANTIBIOTICS AND RELATED SUBSTANCES
(L02) ENDOCRINE THERAPY
ENDOCRINE THERAPY

Medical condition to be studied

Breast cancer female
Breast cancer stage I
Breast cancer stage II
Breast cancer stage III
Breast cancer stage IV
Population studied

Age groups

Adults (18 to < 46 years)
Adults (46 to < 65 years)

Special population of interest

Pregnant women

Estimated number of subjects

2965
Study design details

Main study objective

Our aim is to improve methods for developing measurements of medication exposure in hospital settings. This drug utilisation study will describe patterns of medication use in pregnancy associated breast cancer (PABC) and in breast cancer in non-pregnant women. We will also assess whether time at diagnosis and timing of medication use in pregnancy impacts maternal survival and pregnancy outcomes.

Outcomes

Maternal overall and 5-year relative survival in woman with PABC vs non-PABC patients. Mode of delivery and the following pregnancy outcomes (termination of pregnancy, live birth, stillbirth, preterm birth, small for gestational age SGA) in women with PABC and non-PABC.

Data analysis plan

Descriptive analysis of cancer therapies used to treat breast cancer over the course of a pregnancy (prior to, during, after pregnancy) and during pregnancy (1st, 2nd or 3rd trimester) will be provided. 5-year relative survival analyses will be carried out using e.g. Cox proportional hazard regression and flexible parametric models to elucidate the complex associations between time-since-conception, medication exposure, breast cancer incidence and survival and to control for important confounders. Effects will be presented as relative risk estimates with CI describing the precision of the estimate (95% CI).