J Clin Oncol 2017 Sep 20;35(25):2934-2941. Epub 2017 Jul 20.
Alvaro Lassaletta, Michal Zapotocky, Matthew Mistry, Vijay Ramaswamy, Marion Honnorat, Rahul Krishnatry, Ana Guerreiro Stucklin, Nataliya Zhukova, Anthony Arnoldo, Scott Ryall, Catriona Ling, Tara McKeown, Jim Loukides, James T. Rutka, Peter Dirks, Michael D. Taylor, Shiyi Chen, Ute Bartels, Annie Huang, Eric Bouffet, Cynthia Hawkins, and Uri Tabori, The Hospital for Sick Children, Toronto; Adam Fleming, McMaster Children's Hospital, McMaster University, Hamilton; Shayna Zelcer, Children's Hospital of Western Ontario, London, Ontario; David Eisenstat and Bev Wilson, Stollery Children's Hospital, University of Alberta, Edmonton, Alberta; Anne Sophie Carret, Hospital Sainte Justine; Nada Jabado, McGill University, Montreal; Valerie Larouche, Centre Hospitalier Universitaire de Québec, Québec City, Quebec, Canada; Ofelia Cruz and Carmen de Torres, Hospital Sant Joan de Déu, Barcelona, Spain; Cheng-Ying Ho, University of Maryland School of Medicine, Baltimore, MD; Roger J. Packer, Children's National Health System, Washington, DC; Ruth Tatevossian, Ibrahim Qaddoumi, Julie H. Harreld, James D. Dalton, and David W. Ellison, St Jude Children's Research Hospital, Memphis, TN; Jean Mulcahy-Levy and Nicholas Foreman, Children's Hospital Colorado, Aurora, CO; Matthias A. Karajannis, Shiyang Wang, and Matija Snuderl, New York University Langone Medical Center, New York, NY; Amulya Nageswara Rao and Caterina Giannini, The Mayo Clinic, Rochester, MN; Mark Kieran and Keith L. Ligon, Dana-Farber Cancer Institute, Boston Children's Hospital, Boston, MA; Maria Luisa Garre, Paolo Nozza, Samantha Mascelli, and Alessandro Raso, Istituto Giannina Gaslini, Genoa, Italy; Sabine Mueller and Theodore Nicolaides, University of California, San Francisco, San Francisco, CA; Karen Silva and Romain Perbet, Hospices Civils de Lyon; Alexandre Vasiljevic, Cécile Faure Conter, and Didier Frappaz, Institute of Pediatric Hematology and Oncology, Lyon, France; Sarah Leary and Courtney Crane, Seattle Children's Hospital, Seattle, WA; Aden Chan and Ho-Keung Ng, The Chinese University of Hong Kong, Hong Kong; Zhi-Feng Shi and Ying Mao, Huashan Hospital, Fudan University, Shanghai, People's Republic of China; Elizabeth Finch, University of North Carolina, School of Medicine, Chapel Hill, NC; Peter Hauser, Semmelweis University, Budapest, Hungary; and David Sumerauer and Lenka Krskova, University Hospital Motol, Charles University, 2nd Medical School, Prague, Czech Republic.
Purpose BRAF V600E is a potentially highly targetable mutation detected in a subset of pediatric low-grade gliomas (PLGGs). Its biologic and clinical effect within this diverse group of tumors remains unknown. Patients and Methods A combined clinical and genetic institutional study of patients with PLGGs with long-term follow-up was performed (N = 510). Clinical and treatment data of patients with BRAF V600E mutated PLGG (n = 99) were compared with a large international independent cohort of patients with BRAF V600E mutated-PLGG (n = 180). Results BRAF V600E mutation was detected in 69 of 405 patients (17%) with PLGG across a broad spectrum of histologies and sites, including midline locations, which are not often routinely biopsied in clinical practice. Patients with BRAF V600E PLGG exhibited poor outcomes after chemotherapy and radiation therapies that resulted in a 10-year progression-free survival of 27% (95% CI, 12.1% to 41.9%) and 60.2% (95% CI, 53.3% to 67.1%) for BRAF V600E and wild-type PLGG, respectively ( P < .001). Additional multivariable clinical and molecular stratification revealed that the extent of resection and CDKN2A deletion contributed independently to poor outcome in BRAF V600E PLGG. A similar independent role for CDKN2A and resection on outcome were observed in the independent cohort. Quantitative imaging analysis revealed progressive disease and a lack of response to conventional chemotherapy in most patients with BRAF V600E PLGG. Conclusion BRAF V600E PLGG constitutes a distinct entity with poor prognosis when treated with current adjuvant therapy.