Publications by authors named "O'Regan R"

Objectives: Periprosthetic joint infection (PJI) is a complication of joint arthroplasty and is seen in 1-2% of cases. Since its initiation in 2013, the national outpatient parenteral antimicrobial therapy (OPAT) program has facilitated the outpatient management of intravenous antimicrobials for PJI. This study aims to describe the clinical epidemiology of patients on OPAT with PJI between 2013 and 2021.

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  • The study examines the connection between breast cancer subtypes and CSF cytology results with overall survival among patients with leptomeningeal disease.
  • Out of 69 participants, triple-negative breast cancer was linked to significantly shorter survival compared to ER+/HER2- subtype, while CSF- patients had better overall survival compared to those with positive or not tested CSF results.
  • The findings highlight the importance of breast cancer subtypes and CSF cytology in determining patient prognosis, suggesting that specific subtypes could influence survival outcomes.
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In preclinical studies, p53 loss of function impacts chemotherapy response, but this has not been consistently validated clinically. We trained a TP53-loss phenocopy gene expression signature from pan-cancer clinical samples in the TCGA. In vitro, the TP53-loss phenocopy signature predicted chemotherapy response across cancer types.

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Importance: Adjuvant ovarian function suppression (OFS) with oral endocrine therapy improves outcomes for premenopausal patients with hormone receptor-positive (HR+) breast cancer but adds adverse effects. A genomic biomarker for selecting patients most likely to benefit from OFS-based treatment is lacking.

Objective: To assess the predictive and prognostic performance of the Breast Cancer Index (BCI) for OFS benefit in premenopausal women with HR+ breast cancer.

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The objective of the study is to assess impact of systemic disease (SD) status on overall survival and brain metastasis (BM) control, adopting a novel landmark approach to categorize SD among breast cancer (BC) patients. This single institution retrospective study included BCBM patients who have received stereotactic radiosurgery (SRS) to brain. Separate endpoints [CNS failure-free survival (cFFS), overall survival (OS)] were analyzed from each Landmark (LM): LM1 (3-months), LM2 (6-months).

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Breast cancer is the most common cancer among women worldwide, and estrogen receptor-positive (ER+) breast cancer accounts for a significant proportion of cases. While various treatments are available, endocrine therapies are often the first-line treatment for this type of breast cancer. However, the development of drug resistance poses a significant challenge in managing this disease.

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In this study, we aim to describe the demographic, clinical and imaging characteristics, treatment course and subsequent outcomes of the first 116 cases presenting to a tertiary Dublin hospital with COVID-19 infection and to compare whether ethnic minority background was a risk factor for poorer disease outcomes in this cohort. Of 116 cases analysed, 100 (86%) patients presented from the community, 6 (5%) from care homes and 10 (9%) were existing inpatients. Fifty-four (46%) patients identified as being from an ethnic minority group.

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Background: While the modes of transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are well studied, the risk of transmission in various group settings or activities is less clear. This living scoping review aims to summarize the risk factors of coronavirus disease 2019 (COVID-19) spread in common group activities (e.g.

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Background: The efficacy of CB-103 was evaluated in preclinical models of both ER+ and TNBC. Furthermore, the therapeutic efficacy of combining CB-103 with fulvestrant in ER+ BC and paclitaxel in TNBC was determined.

Methods: CB-103 was screened in combination with a panel of anti-neoplastic drugs.

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Article Synopsis
  • - The study investigated the accuracy and effectiveness of various Rapid Antigen Detection Tests (RADTs) for SARS-CoV-2, comparing them to the standard RT-PCR tests, and examined different testing strategies and settings.
  • - After reviewing 8010 records, 18 studies were included in the analysis, showing that while RADTs had high specificity (>98%), sensitivity varied, particularly favoring samples collected by healthcare workers over self-collected ones, and nasal samples performed better than saliva.
  • - The researchers concluded that more high-quality studies are needed to validate the findings, as the current literature showed a risk of bias and differences in sensitivity, and recommended evaluating testing strategies in real-world scenarios focusing on transmission and incidence rates.
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Triple negative breast cancer (TNBC) is characterized by high rates of disease recurrence after definitive therapy, and median survival of less than 18 months in the metastatic setting. Systemic therapy options for TNBC consist primarily of cytotoxic chemotherapy-containing regimens, and while recently FDA-approved chemo-immunotherapy combinations and antibody-drug conjugates such as Sacituzumab govitecan have improved clinical outcomes, there remains an unmet need for more effective and less toxic therapies. A subset of TNBC expresses the androgen receptor (AR), a nuclear hormone steroid receptor that activates an androgen-responsive transcriptional program, and gene expression profiling has revealed a TNBC molecular subtype with AR expression and luminal and androgen responsive features.

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The expansion of the spectrum of human epidermal growth factor receptor 2 (HER2)-status to HER2-low, defined as HER2 expression of 1+ by immunohistochemistry (IHC) or 2+ by IHC without gene amplification, has made a major impact in the field of oncology. The HER2-low expression has emerged as a targetable biomarker, and anti-HER2 antibody-drug conjugate trastuzumab deruxtecan has shown significant survival benefit in pretreated metastatic HER2-low breast cancer (BC). With these recent data, the treatment algorithm for hormone receptor-positive and triple-negative BC needs to be reconsidered, as approximately half of these BCs are HER2-low.

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Background: The isolation of cell-free DNA (cfDNA) from the bloodstream can be used to detect and analyze somatic alterations in circulating tumor DNA (ctDNA), and multiple cfDNA-targeted sequencing panels are now commercially available for Food and Drug Administration (FDA)-approved biomarker indications to guide treatment. More recently, cfDNA fragmentation patterns have emerged as a tool to infer epigenomic and transcriptomic information. However, most of these analyses used whole-genome sequencing, which is insufficient to identify FDA-approved biomarker indications in a cost-effective manner.

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  • CDK4/6 inhibitors like ribociclib, when combined with a new endocrine therapy (ET), significantly improve progression-free survival (PFS) for patients with hormone receptor-positive, HER2-negative metastatic breast cancer that has progressed on prior therapies.
  • In a phase II, double-blind trial, patients who switched their ET and received ribociclib showed a PFS median of 5.29 months, compared to 2.76 months for those on placebo.
  • The study highlights the effectiveness of modifying treatment in advanced breast cancer, demonstrating a notable benefit in PFS, with rates at 6 and 12 months being much higher for the ribociclib group.
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Several anti-HER2 agents are approved for third-line treatment and beyond (after first-line and second-line); however, no specific treatment strategy is recommended for third-line and beyond. Although these agents improve disease outcomes, HER2-positive metastatic breast cancer remains incurable and there is an unmet need for effective therapies in the later line setting. This review focuses on the development of margetuximab-cmkb, a novel, Fc-engineered, anti-HER2 monoclonal antibody, and its role in the systemic treatment of adult patients with metastatic HER2-positive breast cancer who have received two or more prior anti-HER2 regimens, at least one of which was for metastatic disease.

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Human epidermal growth factor receptor 2 (HER2) overexpression occurs in 15% to 20% of patients with early-stage breast cancers (EBCs). Without HER2-targeted therapy, 30% to 50% of patients relapse within 10 years, many developing incurable metastatic disease. This literature review was designed to identify and validate patient- and disease-related factors associated with recurrence in patients with HER2+ EBC.

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Purpose: The role of neoadjuvant endocrine therapy in the treatment of patients with early-stage, hormone receptor-positive (HR +) breast cancer is not well defined. Tools to better determine which patients may benefit from neoadjuvant endocrine therapy versus chemotherapy or upfront surgery remain an unmet need.

Methods: We assessed the rate of clinical and pathologic complete response (cCR, pCR) among a pooled cohort of patients with early-stage HR + breast cancer who had been randomized to neoadjuvant endocrine therapy or neoadjuvant chemotherapy in two earlier studies to understand better how outcomes varied by Oncotype DX Breast Recurrence Score® assay.

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Brain metastasis arising from breast cancer is associated with a poor prognosis. Various systemic chemotherapy and targeted therapies which are effective against breast cancer often fail to provide benefits against brain metastasis. This is mainly due to limited penetration of the therapies across the blood-brain barrier, and divergent evolution of brain metastasis compared to the primary tumor.

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Inflammatory breast cancer (IBC) is a rare variety of breast cancer accounting for two percent of breast cancer diagnoses in the United States. It is characterized by peau d'orange, breast edema and erythema on physical examination and dermal lymphatic invasion by tumor emboli on histological examination. Micrometastases to lymphatics and bone marrow at the time of diagnosis and angiogenic properties of IBC explain the high propensity of this cancer to relapse and metastasize, its aggressiveness and poor prognosis.

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