104 research outputs found

    SynthEx: a synthetic-normal-based DNA sequencing tool for copy number alteration detection and tumor heterogeneity profiling

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    TCGA head and neck squamous cell carcinoma clinical information of tumors used in comparisons (n = 100). (XLSX 55 kb

    Integrated analysis of RNA and DNA from the phase III trial CALGB 40601 identifies predictors of response to trastuzumab-based neoadjuvant chemotherapy in HER2-positive breast cancer

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    Purpose: Response to a complex trastuzumab-based regimen is affected by multiple features of the tumor and its microenvironment. Developing a predictive algorithm is key to optimizing HER2-targeting therapy. Experimental Design: We analyzed 137 pretreatment tumors with mRNA-seq and DNA exome sequencing from CALGB 40601, a neoadjuvant phase III trial of paclitaxel plus trastuzumab with or without lapatinib in stage II to III HER2-positive breast cancer. We adopted an Elastic Net regularized regression approach that controls for covarying features within high-dimensional data. First, we applied 517 known gene expression signatures to develop an Elastic Net model to predict pCR, which we validated on 143 samples from four independent trials. Next, we performed integrative analyses incorporating clinicopathologic information with somatic mutation status, DNA copy number alterations (CNA), and gene signatures. Results: The Elastic Net model using only gene signatures predicted pCR in the validation sets (AUC ¼ 0.76). Integrative analyses showed that models containing gene signatures, clinical features, and DNA information were better pCR predictors than models containing a single data type. Frequently selected variables from the multiplatform models included amplifications of chromosome 6p, TP53 mutation, HER2-enriched subtype, and immune signatures. Variables predicting resistance included Luminal/ERþ features. Conclusions: Models using RNA only, as well as integrated RNA and DNA models, can predict pCR with improved accuracy over clinical variables. Somatic DNA alterations (mutation, CNAs), tumor molecular subtype (HER2E, Luminal), and the microenvironment (immune cells) were independent predictors of response to trastuzumab and paclitaxel-based regimens. This highlights the complexity of predicting response in HER2-positive breast cancer

    Genomic analysis of oesophageal squamous-cell carcinoma identifies alcohol drinking-related mutation signature and genomic alterations

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    Approximately half of the world's 500,000 new oesophageal squamous-cell carcinoma (ESCC) cases each year occur in China. Here, we show whole-genome sequencing of DNA and RNA in 94 Chinese individuals with ESCC. We identify six mutational signatures (E1–E6), and Signature E4 is unique in ESCC linked to alcohol intake and genetic variants in alcohol-metabolizing enzymes. We discover significantly recurrent mutations in 20 protein-coding genes, 4 long non-coding RNAs and 10 untranslational regions. Functional analyses show six genes that have recurrent copy-number variants in three squamous-cell carcinomas (oesophageal, head and neck and lung) significantly promote cancer cell proliferation, migration and invasion. The most frequently affected genes by structural variation are LRP1B and TTC28. The aberrant cell cycle and PI3K-AKT pathways seem critical in ESCC. These results establish a comprehensive genomic landscape of ESCC and provide potential targets for precision treatment and prevention of the cancer

    Integrated RNA and DNA sequencing reveals early drivers of metastatic breast cancer

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    Breast cancer metastasis remains a clinical challenge, even within a single patient across multiple sites of the disease. Genome-wide comparisons of both the DNA and gene expression of primary tumors and metastases in multiple patients could help elucidate the underlying mechanisms that cause breast cancer metastasis. To address this issue, we performed DNA exome and RNA sequencing of matched primary tumors and multiple metastases from 16 patients, totaling 83 distinct specimens. We identified tumor-specific drivers by integrating known protein-protein network information with RNA expression and somatic DNA alterations and found that genetic drivers were predominantly established in the primary tumor and maintained through metastatic spreading. In addition, our analyses revealed that most genetic drivers were DNA copy number changes, the TP53 mutation was a recurrent founding mutation regardless of subtype, and that multiclonal seeding of metastases was frequent and occurred in multiple subtypes. Genetic drivers unique to metastasis were identified as somatic mutations in the estrogen and androgen receptor genes. These results highlight the complexity of metastatic spreading, be it monoclonal or multiclonal, and suggest that most metastatic drivers are established in the primary tumor, despite the substantial heterogeneity seen in the metastases

    Integrated DNA and RNA Sequencing Reveals Drivers of Endocrine Resistance in Estrogen Receptor Positive Breast Cancer

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    PURPOSE: Endocrine therapy resistance (ETR) remains the greatest challenge in treating patients with hormone receptor–positive breast cancer. We set out to identify molecular mechanisms underlying ETR through in-depth genomic analysis of breast tumors. EXPERIMENTAL DESIGN: We collected pre-treatment and sequential on-treatment tumor samples from 35 patients with estrogen receptor–positive breast cancer treated with neoadjuvant then adjuvant endocrine therapy; 3 had intrinsic resistance, 19 acquired resistance, and 13 remained sensitive. Response was determined by changes in tumor volume neoadjuvantly and by monitoring for adjuvant recurrence. Twelve patients received two or more lines of endocrine therapy, with subsequent treatment lines being initiated at the time of development of resistance to the previous endocrine therapy. DNA whole-exome sequencing and RNA sequencing were performed on all samples, totalling 169 unique specimens. DNA mutations, copy-number alterations, and gene expression data were analyzed through unsupervised and supervised analyses to identify molecular features related to ETR. RESULTS: Mutations enriched in ETR included ESR1 and GATA3. The known ESR1 D538G variant conferring ETR was identified, as was a rarer E380Q variant that confers endocrine hypersensitivity. Resistant tumors which acquired resistance had distinct gene expression profiles compared with paired sensitive tumors, showing elevated pathways including ER, HER2, GATA3, AKT, RAS, and p63 signaling. Integrated analysis in individual patients highlighted the diversity of ETR mechanisms. CONCLUSIONS: The mechanisms underlying ETR are multiple and characterized by diverse changes in both somatic genetic and transcriptomic profiles; to overcome resistance will require an individualized approach utilizing genomic and genetic biomarkers and drugs tailored to each patient

    Fluoroscopic Navigation for Robot-Assisted Orthopedic Surgery

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    Robot-assisted orthopedic surgery has gained increasing attention due to its improved accuracy and stability in minimally-invasive interventions compared to a surgeon's manual operation. An effective navigation system is critical, which estimates the intra-operative tool-to-tissue pose relationship to guide the robotic surgical device. However, most existing navigation systems use fiducial markers, such as bone pin markers, to close the calibration loop, which requires a clear line of sight and is not ideal for patients. This dissertation presents fiducial-free, fluoroscopic image-based navigation pipelines for three robot-assisted orthopedic applications: femoroplasty, core decompression of the hip, and transforaminal lumbar epidural injections. We propose custom-designed image intensity-based 2D/3D registration algorithms for pose estimation of bone anatomies, including femur and spine, and pose estimation of a rigid surgical tool and a flexible continuum manipulator. We performed system calibration and integration into a surgical robotic platform. We validated the navigation system's performance in comprehensive simulation and ex vivo cadaveric experiments. Our results suggest the feasibility of applying our proposed navigation methods for robot-assisted orthopedic applications. We also investigated machine learning approaches that can benefit the medical imaging analysis, automate the navigation component or address the registration challenges. We present a synthetic X-ray data generation pipeline called SyntheX, which enables large-scale machine learning model training. SyntheX was used to train feature detection tasks of the pelvis anatomy and the continuum manipulator, which were used to initialize the registration pipelines. Last but not least, we propose a projective spatial transformer module that learns a convex shape similarity function and extends the registration capture range. We believe that our image-based navigation solutions can benefit and inspire related orthopedic robot-assisted system designs and eventually be used in the operating rooms to improve patient outcomes

    A Study of the Use of Primolut N Tablet as a Contraceptive in the Kumasi Metropolis of Ghana

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    This study investigated the use of Primolut N tablet which contains norethisterone 5mg popularly called N- tablet by users as a precoitalcontraceptive by women in the Kumasi metropolis of Ghana. Clients who called at any of the twenty (20) selected Pharmacies in residential areas within the Kumasi metropolis demanding the drug, with or without valid prescriptions were interviewed using a guide. Of the two hundred and twenty (220) users interviewed, 94% demanded the drug for contraception and 6% for menstrual disorders. Sixty one percent of those demanding it for contraception were between the ages 20-25 years. Respondents preferred theuse of norethisterone tablets as a contraceptive to other methods because it worked for them and they also found it easy and convenient taking a tablet just before coitus than taking daily oral contraceptive pills. Norethisterone is being used as a pre-coital contraceptive, though the efficacy, safety and reliability of the drug for that purpose is unknown. Until these are known, women must be discouraged from using the drug (Afr J Reprod Health 2011; 15[1]: 65-67)

    LCCC 1025: a phase II study of everolimus, trastuzumab, and vinorelbine to treat progressive HER2-positive breast cancer brain metastases

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    Purpose: HER2 + breast cancer (BC) is an aggressive subtype with high rates of brain metastases (BCBM). Two-thirds of HER2 + BCBM demonstrate activation of the PI3K/mTOR pathway driving resistance to anti-HER2 therapy. This phase II study evaluated everolimus (E), a brain-permeable mTOR inhibitor, trastuzumab (T), and vinorelbine (V) in patients with HER2 + BCBM. Patients and methods: Eligible patients had progressive HER2 + BCBM. The primary endpoint was intracranial response rate (RR); secondary objectives were CNS clinical benefit rate (CBR), extracranial RR, time to progression (TTP), overall survival (OS), and targeted sequencing of tumors from enrolled patients. A two-stage design distinguished intracranial RR of 5% versus 20%. Results: 32 patients were evaluable for toxicity, 26 for efficacy. Intracranial RR was 4% (1 PR). CNS CBR at 6 mos was 27%; at 3 mos 65%. Median intracranial TTP was 3.9 mos (95% CI 2.2–5). OS was 12.2 mos (95% CI 0.6–20.2). Grade 3–4 toxicities included neutropenia (41%), anemia (16%), and stomatitis (16%). Mutations in TP53 and PIK3CA were common in BCBM. Mutations in the PI3K/mTOR pathway were not associated with response. ERBB2 amplification was higher in BCBM compared to primary BC; ERBB2 amplification in the primary BC trended toward worse OS. Conclusion: While intracranial RR to ETV was low in HER2 + BCBM patients, one-third achieved CNS CBR; TTP/OS was similar to historical control. No new toxicity signals were observed. Further analysis of the genomic underpinnings of BCBM to identify tractable prognostic and/or predictive biomarkers is warranted. Clinical Trial: (NCT01305941)
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