In:
npj Breast Cancer, Springer Science and Business Media LLC, Vol. 5, No. 1 ( 2019-05-30)
Kurzfassung:
There is a clinical need to predict sensitivity of metastatic hormone receptor-positive and HER2-negative (HR+/HER2−) breast cancer to endocrine therapy, and targeted RNA sequencing (RNAseq) offers diagnostic potential to measure both transcriptional activity and functional mutation. We developed the SET ER/PR index to measure gene expression microarray probe sets that were correlated with hormone receptors ( ESR1 and PGR ) and robust to preanalytical and analytical influences. We tested SET ER/PR index in biopsies of metastastic HR+/HER2− breast cancer against the treatment outcomes in 140 patients. Then we customized the SET ER/PR assay to measure 18 informative, 10 reference transcripts, and sequence the ligand-binding domain (LBD) of ESR1 using droplet-based targeted RNAseq, and tested that in residual RNA from 53 patients. Higher SET ER/PR index in metastatic samples predicted longer PFS and OS when patients received endocrine therapy as next treatment, even after adjustment for clinical-pathologic risk factors (PFS: HR 0.534, 95% CI 0.299 to 0.955, p = 0.035; OS: HR 0.315, 95% CI 0.157 to 0.631, p = 0.001). Mutated ESR1 LBD was detected in 8/53 (15%) of metastases, involving 1−98% of ESR1 transcripts (all had high SET ER/PR index). A signature based on probe sets with good preanalytical and analytical performance facilitated our customization of an accurate targeted RNAseq assay to measure both phenotype and genotype of ER-related transcription. Elevated SET ER/PR was associated with prolonged sensitivity to endocrine therapy in patients with metastatic HR+/HER2− breast cancer, especially in the absence of mutated ESR1 transcript.
Materialart:
Online-Ressource
ISSN:
2374-4677
DOI:
10.1038/s41523-019-0111-0
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2019
ZDB Id:
2843288-5
