title: Breast cancer risk in hyperprolactinemia: a population-based cohort study and meta-analysis of the literature.
abstract: OBJECTIVE
  To enhance the precision of the risk estimate for breast cancer in hyperprolactinemia patients by collecting more data and pooling our results with available data from former studies in a meta-analysis.
  
  
  METHODS
  Population-based cohort study and meta-analysis of the literature.
  
  
  METHODS
  Using nationwide registries, we identified all patients with a first-time diagnosis of hyperprolactinemia during 1994-2012 including those with a new breast cancer diagnoses after the start of follow-up. We calculated standardised incidence ratios (SIRs) as a measure of relative risk (RR) using national cancer incidence rates. We performed a meta-analysis, combining data from our study with data in the existing literature.
  
  
  RESULTS
  We identified 2457 patients with hyperprolactinemia and 20 breast cancer cases during 19,411 person-years of follow-up, yielding a SIR of 0.99 (95% CI 0.60-1.52). Data from two additional cohort studies were retrieved and analyzed. When the three risk estimates were pooled, the combined RR was 1.04 (95% CI 0.75-1.43).
  
  
  CONCLUSIONS
  We found no increased risk of breast cancer among patients with hyperprolactinemia.
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark.
authors.forename: O M
authors.initials: OM
authors.lastname: Dekkers
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark.
authors.forename: V
authors.initials: V
authors.lastname: Ehrenstein
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Bengtsen
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark.
authors.forename: D Kormendine
authors.initials: DK
authors.lastname: Farkas
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark.
authors.forename: A M
authors.initials: AM
authors.lastname: Pereira
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark.
authors.forename: H T
authors.initials: HT
authors.lastname: Sørensen
authors.affiliation: Department of Clinical EpidemiologyAarhus University Hospital, Aarhus, Denmark, Section of EndocrinologyDepartments of MedicineClinical EpidemiologyLeiden University Medical Center, Leiden, The NetherlandsDepartment of Endocrinology and Internal MedicineAarhus University Hospital, Aarhus, Denmark joj@clin.au.dk.
authors.forename: J O L
authors.initials: JO
authors.lastname: Jørgensen
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D006966:Hyperprolactinemia / Q000175:diagnosis* / Q000453:epidemiology*; D011159:Population Surveillance; D012042:Registries; D012307:Risk Factors