Immunotherapy in rare histologies of breast cancer: challenges, opportunities, and future perspectives.

Purpose Of Review: Immunotherapy has transformed the management of several malignancies, yet its role in rare breast cancer histologies remains poorly defined due to limited research and few dedicated clinical trials. This review critically assesses current knowledge and emerging opportunities for immunotherapy in these uncommon breast cancer subtypes.

Recent Findings: Rare breast cancer histologies exhibit heterogeneous immunogenicity, including variable expression of programmed death-ligand 1 (PD-L1), differing levels of tumor-infiltrating lymphocytes (TILs), and distinct mutational burdens.

Comparative analysis of Denosumab and Zoledronic acid in advanced breast cancer patients receiving CDK4/6 inhibitors.

A comparative analysis of Denosumab (DMAB) and Zoledronic Acid (ZA) was conducted in a real-world cohort of 864 patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer with bone metastases, who were undergoing CDK4/6 inhibitors plus endocrine therapy. We evaluated the time to first skeletal-related events (SREs), progression-free survival (PFS), and overall survival (OS). To adjust for confounding variables, we utilized propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) methodologies.

ESR1 testing on FFPE samples from metastatic lesions in HR + /HER2- breast cancer after progression on CDK4/6 inhibitor therapy.

Mutations in ESR1 play a critical role in resistance to endocrine therapy (ET) in hormone receptor-positive (HR +)/HER2- metastatic breast cancer (MBC). Testing for ESR1 mutations is essential for guiding treatment with novel oral selective estrogen receptor degraders (SERDs) like elacestrant or camizestrant. While most studies have utilized liquid biopsy (LB) for mutation detection, the role of formalin-fixed paraffin-embedded (FFPE) tissue biopsy in this context remains unclear.

Prognostic impact of tumor-infiltrating lymphocytes in HER2+ metastatic breast cancer receiving first-line treatment.

Breast cancer (BC) is a leading cause of death among women, with approximately 30% HER2-positive (HER2+). Although HER2-targeted therapies have improved outcomes for patients with HER2+ metastatic breast cancer (mBC), clinical challenges and prognostic variability remain. Tumor-infiltrating lymphocytes (TILs) have emerged as prognostic and predictive biomarkers in various tumors, including BC, but their role in HER2+ mBC is poorly understood.

Survival Following CDK4/6 Inhibitor Therapy for Hormone Receptor-Positive, ERBB2-Negative Metastatic Breast Cancer.

Importance: Endocrine therapy (ET) combined with cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) agents is the standard first-line treatment for patients with hormone receptor-positive, ERBB2 (formerly HER2 or HER2/neu)-negative metastatic breast cancer. However, optimal therapy after tumor progression to ET plus CDK4/6i remains unclear.

Objective: To evaluate progression-free survival (PFS) and overall survival (OS) in the clinical practice setting in patients with hormone receptor-positive, ERBB2-negative metastatic breast cancer following progression with ET plus CDK4/6i.

Advancing treatment choices: CDK4/6 inhibitor switching in HR+/HER2- metastatic breast cancer.

Purpose: CDK4/6 inhibitors (CDK4/6i) use has revolutionized the treatment of hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) metastatic breast cancer. The choice of a specific CDK4/6i may be influenced by adverse events (AEs). Recently, the Italian Medicines Agency (AIFA) approved the possibility of switching between CDK4/6i for unacceptable toxicity.

Oral selective estrogen receptor degraders for breast cancer treatment: focus on pharmacological differences.

Purpose: The management of hormone receptor-positive (HR +) breast cancer (BC) relies on endocrine therapy (ET), with a primary focus on disrupting estrogen receptor (ER) signaling due to its critical role in BC tumorigenesis and progression. While effective for both early-stage and advanced breast cancers, ET frequently encounters resistance mechanisms, including both ligand-dependent and ligand-independent trajectories, ultimately leading to disease progression.

Methods: We searched PubMed, EMBASE and Scopus databases to review the current evidence on the use of novel oral selective estrogen receptor degraders (SERDs) for the treatment of HR+ BC.

The Safety and Suitability of DNA Sequencing of Tissue Biopsies Performed on Patients Referred to a Phase I Unit.

Background: Early-phase clinical trials offer a unique opportunity for patients with cancer. These trials often mandate biopsies to collect tumor tissue for research purposes, requiring patients to undergo invasive procedures. Some trials mandate molecular prescreening, but the success of these analyses relies on the quality and quantity of the tested materials.

Clinical impact of drug-drug interactions on abemaciclib in the real-world experience of AB-ITALY study.

Abemaciclib demonstrated clinical benefit in women affected by HR+/HER2- advanced breast cancer (aBC). Drug-drug interactions (DDIs) can lead to reduced treatment efficacy or increased toxicity. This retro-prospective study aimed to evaluate outcomes, DDIs' impact, and toxicities of abemaciclib combined with endocrine therapy in a real-world setting.

Neoadjuvant therapy in hormone Receptor-Positive/HER2-Negative breast cancer.

Neoadjuvant therapy is commonly used in patients with locally advanced or inoperable breast cancer (BC). Neoadjuvant chemotherapy (NACT) represents an established treatment modality able to downstage tumours, facilitate breast-conserving surgery, yet also achieve considerable pathologic complete response (pCR) rates in HER2-positive and triple-negative BC. For patients with HR+/HER2- BC, the choice between NACT and neoadjuvant endocrine therapy (NET) is still based on clinical and pathological features and not guided by biomarkers of defined clinical utility, differently from the adjuvant setting where gene-expression signatures have been widely adopted to drive decision-making.

New steps on an old path: Novel estrogen receptor inhibitors in breast cancer.

Estrogen receptor (ER) signaling represents the main driver of tumor growth and survival in hormone receptor positive (HR+) breast cancer (BC). Thus, endocrine therapy (ET) alone or in combination with targeted agents constitutes the mainstay of the treatment for this BC subtype. Despite its efficacy, intrinsic or acquired resistance to ET occurs in a large proportion of cases, mainly due to aberrant activation of ER signaling (i.