Citations

Abstract INTRODUCTION Patient derived xenografts (PDX) may better reflect individual patient (pt) tumor biology; however, the feasibility of collecting PDX from percutaneous tumor biopsies (PTB) in the neoadjuvant setting is unknown. Furthermore, drug response phenotypes observed in PDX have not been prospectively compared to the corresponding pt clinical outcomes. METHODS The Breast Cancer Genome Guided Therapy Study (BEAUTY) is a prospective Mayo study of pts with high-risk breast cancer treated with neoadjuvant weekly paclitaxel (T) +/- trastuzumab followed by anthracycline based chemotherapy. PTB (at baseline) and residual surgical tissue (after all chemotherapy) are obtained for next generation sequencing (NGS) and PDX. Tumor biopsies (1-2 cores from 14 gauge needle) were implanted with Matrigel <1 hour of collection in the flanks of NOD-SCID or NSG mice. Low dose estradiol was supplemented in the drinking water. Primary outgrowth rate was defined as PDX tumor volume >50 mm3. Take rate was defined as development of at least 1 stably transplantable xenograft line/pt. To determine whether clinical T response assessed by MRI corresponded with in vivo T response, pretreatment PDX from 5 pts were injected into NOD-SCID mice (20 mice per pt PDX) and when tumors reached 100-200mm3, mice were randomized to no treatment vs T (20 mg/kg, ip. every 3-4 days). Two of these 5 patients had a MRI response defined as >30% decrease in longest lesion. RESULTS Pretreatment PTB from 81 unique pts were implanted in 251 mice (2-4 mice/pt). PDX outgrowth rates were 33.3% (27/81 pts) and 22 stable PDX were established (overall take rate 27.2%). Take rates were as follows: triple negative breast cancer (46%; 13/28); HER2 (27%; 6/22), Luminal B (13%; 3/22), and luminal A (0%; 0/9). Residual surgical tumor (after all treatment) from 17 pts was injected into 85 mice (average 5 mice/pt) and the initial outgrowth rate was 23% (4/17) with 3 stably transplantable lines established. PDX, derived from pretreatment PTB of 5 pts (2 responders and 3 non-responders), were assessed for in vivo T response. The size of the T treated group was significantly smaller than the no treatment group for the PDX derived from the 2 clinical responders, with complete disappearance of tumor by 18 days. In contrast, the PDX derived from the 3 clinical non-responders had no evidence for T response. CONCLUSIONS We have demonstrated the feasibility of using PTB to establish PDX in a prospective neoadjuvant clinical study and have demonstrated similar T drug response phenotypes in in the PDX as seen in the corresponding pt. These data suggest that PDX generated prospectively may be useful for biomarker validation and the development and individualization of new drug therapy. Funded by the Mayo Clinic Center for Individualized Medicine and the Mayo Clinic Cancer Center Citation Format: Jia Yu, Ping Yin, Bowen Gao, Jason P. Sinnwell, Ann M. Moyer, Daniel W. Visscher, Amy L. Conners, Travis J. Dockter, Krishna R. Kalari, Xiaojia Tang, Kevin J. Thompson, Hugues Sicotte, Douglas W. Mahoney, Steven N. Hart, Peter T. Vedell, Poulami Barman, Katie N. Jones, Sarah A. McLaughlin, John A. Copland, Alvaro Moreno Aspitia, Donald W. Northfelt, Richard J. Gray, Vera J. Suman, Jeanette E. Eckel Passow, Eric D. Wieben, James N. Ingle, Zhenkun Lou, Gianrico Farrugia, Richard Weinshilboum, Matthew P. Goetz, Judy C. Boughey, Liewei Wang. Feasibility of using percutaneous tumor biopsies from a prospective neoadjuvant breast cancer study to develop patient derived xenografts and assess in vivo chemotherapy sensitivity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1195. doi:10.1158/1538-7445.AM2014-1195

Abstract Background: Treatment options for women with ovarian cancer remain very limited and acquired resistance to current therapies is very common. Altered DNA repair capability in epithelial ovarian cancer (EOC) may underlie response to both standard therapy and novel treatments, such as PARP inhibitors. Molecular sub-classification of high-grade serous ovarian cancer (HG-SOC) may uncover potential drug targets and possible mechanisms of drug resistance. Understanding the contribution of DNA repair and other driver mutations to drug response and resistance requires the development of molecularly annotated preclinical models reflective of the clinic. Methods: A patient derived xenograft (PDX) cohort has been generated from consecutive, chemotherapy-naïve human HG-SOC and stratified according to in vivo response to standard chemotherapy, DNA repair capability and molecular characteristics, including next generation sequencing by Foundation Medicine. Resistance to therapy is driven by re-treating relapsed PDX in vivo providing invaluable “paired samples” (pre and post drug treatment), which are difficult to obtain from patients, to allow clonal evolution analysis of mechanisms of drug response and resistance. Results: The xenograft success rate was 83%. Of ten HG-SOC PDX, all exhibited mutations in TP53, five in BRCA1/2 (two of which were germline) and two were methylated for BRCA1. In vivo cisplatin response, determined as platinum sensitive (progression-free interval (PFI) ≥100 d, n=4), platinum resistant (PFI <100 d, n=3) or platinum refractory (n=3), was largely consistent with patient outcome. Three of four platinum sensitive HG-SOC PDX contained DNA repair gene mutations, and the fourth was methylated for BRCA1. In contrast, all three platinum refractory PDX overexpressed dominant oncogenes (CCNE1, LIN28B and/or BCL2). Molecular analysis of this cohort has revealed actionable targets for novel therapeutic strategies. In vivo studies, including with PARP inhibitors, are underway. Conclusion: PDX with histologic, molecular and therapeutic annotation, as well as clinical outcome data allow interrogation of molecular aberrations and drug resistance in vivo. This will inform targeting of novel therapies and the design of clinical trials for women. Citation Format: Monique D. Topp, Lynne Hartley, Michele Cook, Valerie Heong, Emma Boehm, Lauren McShane, Jan Pyman, Orla McNally, Sumi Ananda, Maria I. Harell, Dariush Etemadmoghadam, Laura Galletta, Kathryn Alsop, Gillian Mitchell, Stephen B. Fox, Jeff B. Kerr, Karla J. Hutt, Scott H. Kaufmann, Australian Ovarian Cancer Study (AOCS), Elizabeth M. Swisher, David D. Bowtell, Matthew M. Wakefield, Clare L. Scott. Using molecularly characterized patient-derived models to delineate underlying drivers and vulnerabilities of epithelial ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference: Cancer Susceptibility and Cancer Susceptibility Syndromes; Jan 29-Feb 1, 2014; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(23 Suppl):Abstract nr 38. doi:10.1158/1538-7445.CANSUSC14-38

Shear wave elastography with ultrasound applies an acoustic radiation force to generate shear waves in viscoelastic soft tissue. To address the need for more effective simulation tools that model shear waves generated by an applied acoustic radiation force, three-dimensional (3D) finite difference programs that simulate propagation of shear waves in an isotropic, homogeneous medium have been created. These programs simulate shear wave propagation in elastic and viscoelastic soft tissue models. The 3D finite difference implementation combines an explicit time-stepping approach and a staggered spatial grid with an absorbing boundary condition that reduces boundary reflections. The acoustic radiation force in these simulations is quickly and accurately simulated in FOCUS (http://www.egr.msu.edu/~fultras-web) for a focused linear ultrasound array with an f/# of 2. The compressional wave speed is 1500 m/s and the shear wave speed is 1.5m/s in the elastic and viscoelastic tissue models, and the shear viscosity is 1 Pa·s in the viscoelastic model. The simulation completes 90,000 time steps of a 10 ms simulation in an 80 mm × 80 mm × 80 mm region with spatial sampling equal to the wavelength of compressional component in three days on a 3.4 MHz Intel i7 processor. [Supported in part by NIH Grants R01EB012079 and R01DK092255.]

We implemented a three-dimensional solver for simulating the ultrasound radiation force induced shear wave motion in viscoelastic media using a mapped Chebyshev pseudospectral method. The solver used a body force field that is simulated by the Field II program as the excitation. Then, a velocity-stress formulation was used to calculate the shear wave motion. We used a Voigt model to describe tissue viscoelasticity, and the viscosity is introduced by memory variables and auxiliary differential equations. The top boundary of the domain had a fixed boundary condition to mimic the interaction between an ultrasound probe and the tissue surface. All other sides of the domain were surrounded by perfectly matched layers to minimize the reflections. Time stepping was implemented with the LSODE integrator with variable step sizes. Results show that the waveform of the simulated shear wave is close to experimental observations and equivalent FEM simulations. We used a Fourier-based method to estimate the phase velocities of the shear waves between 100–1000 Hz and a nonlinear regression to estimate the Voigt model parameters. The reconstructions matched within 10% error compared with the true values.

ABSTRACT We compared an FDA-cleared rapid (<20 min) PCR assay (Cobas Liat; Roche Diagnostics) to our routine influenza A and B real-time PCR assay (Simplexa Flu A/B & RSV Direct; Focus Diagnostics) using respiratory swabs ( n = 197). The Cobas Liat influenza A and B assays demonstrated sensitivities of 99.2% (123/124) and 100% (23/23), respectively, while showing a specificity of 100% for each target.

SummaryPatient‐specific primers from 10 children/adolescents with Burkitt leukaemia (BL) ± central nervous system disease who were treated with French‐British‐American/Lymphome Malins de Burkitt 96 C1 plus rituximab were developed from diagnostic blood/bone marrow. Minimal residual disease (MRD) was assessed by real‐time polymerase chain reaction at the end of induction (EOI) and consolidation (EOC). Seventy per cent (7/10) and 71% (5/7) were MRD‐positive at EOI and EOC, respectively, with no disease recurrences. MRD after induction and consolidation did not predict relapse and subsequent therapy appeared to eliminate MRD. Thus, assessing MRD at a later time point is warranted in future trials to determine its clinical significance.

Purpose Carpal tunnel syndrome is a common entrapment neuropathy. When conservative management fails to relieve symptoms, carpal tunnel surgery is indicated. The surgical exposure for this procedure is commonly based on variable anatomic landmarks. The purpose of this study was to describe a fixed, easily referenced anatomical landmark for the distal extension of the transverse carpal ligament, the “Cup of Diogenes.” Materials and Methods Topographical landmarks including Kaplan cardinal line, palmaris tendon, and distal palmer crease were marked on six fresh frozen cadaveric wrist and hand specimens. The apex of the Cup of Diogenes is determined to be the confluence of the thenar and hypothenar musculature of the palm. Wrists were dissected and the distance between these landmarks and the superficial palmar arch, median nerve, transverse carpal ligament, and ulnar nerve were measured. Results In all specimens, the ulnar nerve was ulnar to this the apex of the Cup of Diogenes, while the median nerve was radial. The apex was proximal in all specimens to the superficial palmar arch. The apex marked the distal extent of the transverse carpal ligament in all specimens. Discussion Based on our results, we feel the apex of the Cup of Diogenes is a consistent, fixed anatomical marker for the distal extent of the transverse carpal ligament, marking a safe zone in the palm for surgical planning of incisions. Level of Evidence Level V - Therapeutic