Browsing by Author "Gomez, Daniel"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Clinical utility of next-generation sequencing-based ctDNA testing for common and novel ALK fusions
    (2021) Mondaca, Sebastian; Lebow, Emily S.; Namakydoust, Azadeh; Razavi, Pedram; Reis-Filho, Jorge S.; Shen, Ronglai; Offin, Michael; Tu, Hai-Yan; Murciano-Goroff, Yonina; Xu, Chongrui; Makhnin, Alex; Martinez, Andres; Pavlakis, Nick; Clarke, Stephen; Itchins, Malinda; Lee, Adrian; Rimner, Andreas; Gomez, Daniel; Rocco, Gaetano; Chaft, Jamie E.; Riely, Gregory J.; Rudin, Charles M.; Jones, David R.; Li, Mark; Shaffer, Tristan; Hosseini, Seyed Ali; Bertucci, Caterina; Lim, Lee P.; Drilon, Alexander; Berger, Michael F.; Benayed, Ryma; Arcila, Maria E.; Isbell, James M.; Li, Bob T.
    Objectives: Liquid biopsy for plasma circulating tumor DNA (ctDNA) next-generation sequencing (NGS) can detect ALK fusions, though data on clinical utility of this technology in the real world is limited. Materials and Methods: Patients with lung cancer without known oncogenic drivers or who had acquired resistance to therapy (n = 736) underwent prospective plasma ctDNA NGS. A subset of this cohort (n = 497) also had tissue NGS. We evaluated ALK fusion detection, turnaround time (TAT), plasma and tissue concordance, matching to therapy, and treatment response. Results: ctDNA identified an ALK fusion in 21 patients (3%) with a variety of breakpoints and fusion partners, including EML4, CLTC, and PON1, a novel ALK fusion partner. TAT for ctDNA NGS was shorter than tissue NGS (10 vs. 20 days; p < 0.001). Among ALK fusions identified by ctDNA, 93% (13/14, 95% CI 66%- 99%) were concordant with tissue evaluation. Among ALK fusions detected by tissue NGS, 54% (13/24, 95% CI 33%-74%) were concordant with plasma ctDNA. ctDNA matched patients to ALK-directed therapy with subsequent clinical response, including four patients matched on the basis of ctDNA results alone due to inadequate or delayed tissue testing. Serial ctDNA analysis detected MET amplification (n = 2) and ALK G1202R mutation (n = 2) as mechanisms of acquired resistance to ALK-directed therapy. Conclusion: Our findings support a complementary role for ctDNA in detection of ALK fusions and other alterations at diagnosis and therapeutic resistance settings.
  • Thumbnail Image
    Item
    I would walk 500 miles (if it paid): Vouchers and school choice in Chile
    (PERGAMON-ELSEVIER SCIENCE LTD, 2011) Chumacero, Romulo A.; Gomez, Daniel; Paredes, Ricardo D.
    One of the pillars of the educational voucher system is that competition among schools to attract students would improve the quality of the education. Surveys to parents and previous work suggested that families rank the distance of the school from their home as the most important factor for choosing a school. They also suggest that parents largely ignore the results of standardized tests. We use a novel data-set which includes precise measures of the distance between homes and schools to analyze the determinants of school choice in Chile. Economic theory suggests, and the estimations confirm, that parents consider quality and the location when choosing schools. The paper quantifies the relevant trade-offs. (C) 2011 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    School choice and information
    (UNIV CHILE DEPT ECONOMICS, 2012) Gomez, Daniel; Chumacero, Romulo A.; Paredes, Ricardo D.
    One of the pillars of the educational voucher system is that competition between schools to attract students would improve the quality of the education provided. Surveys in Chile have suggested that parents are not aware of the performance of their children's schools. In this paper, we assess the effect of public information of school quality on the school choice by parents. We use a data set which includes measurements of the distance between homes and schools, and the performance of the school measured by a standardized tests and the school fee for two distinct periods (1996 and 2003). Whereas in 1996, information regarding school performance was scarce, it was widespread in 2003. We conclude that regardless of these considerations, school performance is an important determinant of school choice. Thus, parents appear to act "as if" they knew it when choosing a school. Nevertheless, making public the information regarding the performance of the schools has made it a more important factor in choosing a school.