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4 result(s) for "Dontchos, Brian"
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A prospective study of HER3 expression pre and post neoadjuvant therapy of different breast cancer subtypes: implications for HER3 imaging therapy guidance
Purpose HER3, a member of the EGFR receptor family, plays a central role in driving oncogenic cell proliferation in breast cancer. Novel HER3 therapeutics are showing promising results while recently developed HER3 PET imaging modalities aid in predicting and assessing early treatment response. However, baseline HER3 expression, as well as changes in expression while on neoadjuvant therapy, have not been well-characterized. We conducted a prospective clinical study, pre- and post-neoadjuvant/systemic therapy, in patients with newly diagnosed breast cancer to determine HER3 expression, and to identify possible resistance mechanisms maintained through the HER3 receptor. Experimental design The study was conducted between May 25, 2018 and October 12, 2019. Thirty-four patients with newly diagnosed breast cancer of any subtype (ER ± , PR ± , HER2 ±) were enrolled in the study. Two core biopsy specimens were obtained from each patient at the time of diagnosis. Four patients underwent a second research biopsy following initiation of neoadjuvant/systemic therapy or systemic therapy which we define as neoadjuvant therapy. Molecular characterization of HER3 and downstream signaling nodes of the PI3K/AKT and MAPK pathways pre- and post-initiation of therapy was performed. Transcriptional validation of finings was performed in an external dataset (GSE122630). Results Variable baseline HER3 expression was found in newly diagnosed breast cancer and correlated positively with pAKT across subtypes (r = 0.45). In patients receiving neoadjuvant/systemic therapy, changes in HER3 expression were variable. In a hormone receptor-positive (ER +/PR +/HER2-) patient, there was a statistically significant increase in HER3 expression post neoadjuvant therapy, while there was no significant change in HER3 expression in a ER +/PR +/HER2+ patient. However, both of these patients showed increased downstream signaling in the PI3K/AKT pathway. One subject with ER +/PR −/HER2− breast cancer and another subject with ER +/PR +/HER2 + breast cancer showed decreased HER3 expression. Transcriptomic findings, revealed an immune suppressive environment in patients with decreased HER3 expression post therapy. Conclusion This study demonstrates variable HER3 expression across breast cancer subtypes. HER3 expression can be assessed early, post-neoadjuvant therapy, providing valuable insight into cancer biology and potentially serving as a prognostic biomarker. Clinical translation of neoadjuvant therapy assessment can be achieved using HER3 PET imaging, offering real-time information on tumor biology and guiding personalized treatment for breast cancer patients.
Systematic tissue collection during clinical breast biopsy is feasible, safe and enables high-content translational analyses
Systematic collection of fresh tissues for research at the time of diagnostic image-guided breast biopsy has the potential to fuel a wide variety of innovative studies. Here we report the initial experience, including safety, feasibility, and laboratory proof-of-principle, with the collection and analysis of research specimens obtained via breast core needle biopsy immediately following routine clinical biopsy at a single institution over a 14-month period. Patients underwent one or two additional core biopsies following collection of all necessary clinical specimens. In total, 395 patients were approached and 270 consented to the research study, yielding a 68.4% consent rate. Among consenting patients, 238 lesions were biopsied for research, resulting in 446 research specimens collected. No immediate complications were observed. Representative research core specimens showed high diagnostic concordance with clinical core biopsies. Flow cytometry demonstrated consistent recovery of hundreds to thousands of viable cells per research core. Among a group of HER2 + tumor research specimens, HER2 assessment by flow cytometry correlated highly with immunohistochemistry (IHC) staining, and in addition revealed extensive inter- and intra-tumoral variation in HER2 levels of potential clinical relevance. Suitability for single-cell transcriptomic analysis was demonstrated for a triple-negative tumor core biopsy, revealing substantial cellular diversity in the tumor immune microenvironment, including a prognostically relevant T cell subpopulation. Thus, collection of fresh tissues for research purposes at the time of diagnostic breast biopsy is safe, feasible and efficient, and may provide a high-yield mechanism to generate a rich tissue repository for a wide variety of cross-disciplinary research.
Radiofrequency identification tag localization is comparable to wire localization for non-palpable breast lesions
PurposeRadiofrequency identification (RFID) tag localization (TL) is a technique of localizing non-palpable breast lesions that can be performed prior to surgery. We sought to evaluate whether TL is comparable to wire localization (WL) in regard to specimen size, operative time, and re-excision rate.MethodsA retrospective cohort analysis was performed on TL and WL excisional biopsies and lumpectomies performed by 5 surgeons at 2 institutions. Cases were stratified by surgery type and surgical indication. Associations between localization technique and specimen volume, operative time, and re-excision rate were assessed by univariate and multivariate analyses.ResultsA total of 503 procedures were included, 147 TL (29.2%) and 356 WL (70.8%). Nineteen (12.9%) RFID tags were placed before surgery, ranging 1–22 days. All intended targets were removed. TL and WL excisional biopsy and lumpectomy specimen volumes were similar (p = 0.560 and 0.494). TL and WL excisional biopsy and lumpectomy + SLNB operative times were similar (p = 0.152 and 0.158), but TL lumpectomies without SLNB took longer than WL (57 min vs 49 min; p = 0.027). Re-excision rates were similar by surgical procedure (p = 0.615), surgical indication (DCIS p = 0.145; invasive carcinoma p = 0.759), and confirmed by multivariable analysis (OR 0.754, 95% CI 0.392–1.450; p = 0.397).ConclusionsTL has similar surgical outcomes to WL with added benefit that TL can occur prior to the day of surgery. TL is an acceptable alternative to WL and should be considered for non-palpable breast lesions.