73P microRNA expression profiles of single hormone receptor-positive breast cancers

microRNA Expression Profile in Single Hormone Receptor-Positive Breast Cancers is Mainly Dependent on HER2 Status—A Pilot Study

Estrogen (ER) and progesterone (PgR) receptors and HER2 are crucial in the assessment of breast cancer specimens due to their prognostic and predictive significance. Single hormone receptor-positive breast cancers are less common and their clinical course is less favorable than ER(+)/PgR(+) tumors. Their molecular features, especially microRNA (miRNA) profiles, have not been investigated to date. Tumor specimens from 36 chemonaive breast cancer patients with known ER and PgR status (18 ER(+)/PgR(&minus

ER-/PgR+ breast cancer is a separate entity characterized by distinct phenotype: Comprehensive reevaluation of cases from Polish and Hungarian centers.

e12554 Background: ER negative (-)/PgR positive (+) breast cancer (BC) is very uncommon and questioned by many experts. We comprehensively reevaluated ER-/PgR+ BCs in the large cohort from Polish and Hungarian centers. Methods: FFPE blocks from 105 ER-/PgR+ tumors (45 breast biopsies and 64 post-operative samples from tumors not exposed to systemic therapy) were collected from 10 Polish and 3 Hungarian centers. In 60 cases available original slides with ER/PgR staining underwent reevaluation by 3 pathologists (MK, RP, WB) for ER and PgR expression by ASCO/CAP criteria. Subsequently, all samples were stained with 3 antibodies against ER (Dako monoclonal (MC) mouse anti-ERα, clone 1D5; Dako …