Ontology highlight
ABSTRACT: Background
Recent pre-clinical studies indicate that activated progesterone receptor (PR) (particularly the PR-B isoform) binds to oestrogen receptor-α (ER) and reprogrammes transcription toward better breast cancer outcomes. We investigated whether ER and PR-B interactions were present in breast tumours and associated with clinical parameters including response to aromatase inhibitors.Methods
We developed a proximity ligation assay to detect ER and PR-B (ER:PR-B) interactions in formalin-fixed paraffin-embedded tissues. The assay was validated in a cell line and patient-derived breast cancer explants and applied to a cohort of 229 patients with ER-positive and HER2-negative breast cancer with axillary nodal disease.Results
Higher frequency of ER:PR-B interaction correlated with increasing patient age, lower tumour grade and mitotic index. A low frequency of ER:PR-B interaction was associated with higher risk of relapse. In multivariate analysis, ER:PR-B interaction frequency was an independent predictive factor for relapse, whereas PR expression was not. In subset analysis, low frequency of ER:PR-B interaction was predictive of relapse on adjuvant aromatase inhibitor (HR 4.831, p = 0.001), but not on tamoxifen (HR 1.043, p = 0.939).Conclusions
This study demonstrates that ER:PR-B interactions have utility in predicting patient response to adjuvant AI therapy.
SUBMITTER: Snell CE
PROVIDER: S-EPMC6265321 | biostudies-literature | 2018 Nov
REPOSITORIES: biostudies-literature
Snell Cameron E CE Gough Madeline M Liu Cheng C Middleton Kathryn K Pyke Christopher C Shannon Catherine C Woodward Natasha N Hickey Theresa E TE Armes Jane E JE Tilley Wayne D WD
British journal of cancer 20181109 11
<h4>Background</h4>Recent pre-clinical studies indicate that activated progesterone receptor (PR) (particularly the PR-B isoform) binds to oestrogen receptor-α (ER) and reprogrammes transcription toward better breast cancer outcomes. We investigated whether ER and PR-B interactions were present in breast tumours and associated with clinical parameters including response to aromatase inhibitors.<h4>Methods</h4>We developed a proximity ligation assay to detect ER and PR-B (ER:PR-B) interactions in ...[more]