Transcripts with Retained H/ACA Box SnoRNA Sequences As Biomarkers for Estrogen Dependence in Lum-B Breast Carcinomas

RATIONALE: The primary treatment for estrogen receptor-positive breast cancer relies on estrogen receptor inhibitors. However, responses to hormonal therapy can vary significantly, especially in luminal B breast cancer, necessitating adjuvant chemotherapy for some patients. The Oncotype DX Breast Recurrence Score is the preferred test for determining the most suitable therapy for these patients, providing a Recurrence Score that characterizes the tumor and guides treatment recommendations. Despite its validation, its optimal use in intermediate-risk patients is still unclear. OBJECTIVES: Primary Objective: \- Measure whether the expression of mRNAs extracted from paraffin-embedded tissue is associated with the results of the Oncotype DX test. The primary objective is to evaluate the association between selected mRNA expressions from paraffin-embedded luminal B breast cancer tissue and Oncotype DX test results. This aims to improve current molecular clinical tests and identify new biomarkers for response to anti-estrogen therapy, particularly in luminal B patients with inadequate responses. Secondary Objectives: * Assess concordance of mRNA analysis results from paraffin-embedded versus "fresh frozen" tissue. * Evaluate if mRNA expression levels from paraffin-embedded tissue provide additional characterization for low-risk luminal B patients who do not respond effectively to anti-estrogen therapy. ENDPOINTS: Primary Endpoint: Measure potential mRNA biomarker expression values in therapy response groups identified by the Oncotype DX score (low-risk and high-risk). Secondary Endpoints: * Measure abundance values of potential mRNA biomarkers from both analysis techniques. * Calculate treatment response parameters at 36-60 months (Relapse-Free Survival - RFS, Distant Recurrence-Free Survival - DRFS). STUDY DESIGN: This study will analyze specific mRNAs in luminal B breast cancer patients by collecting and examining both "fresh frozen" and paraffin-embedded tumor tissues. qPCR will evaluate mRNA expressions of WIPI1, STAT5B, SMAP2, MED24, NCOA3, NCOA7, CCAR1, along with isoforms of EIF4A1, EIF4A2, TAF1D, and UBAP2L. Results will be correlated with Oncotype DX outcomes and diagnostic parameters regarding treatment response. Samples will be collected per standard procedures, ensuring patient treatment aligns with clinical practices, with follow-up data monitored accordingly.

Sex

Female

Minimum age

18 Years

Inclusion Criteria:

* Patients with luminal B breast cancer who have undergone the Oncotype DX test at our pathology center, with tissue material available or expected to become available during the enrollment period.
* Age ≥ 18 years
* Informed consent

Exclusion Criteria:

none