title: Comparison of performance of various tumour response criteria in assessment of regorafenib activity in advanced gastrointestinal stromal tumours after failure of imatinib and sunitinib.
abstract: OBJECTIVE
  To compare performance of various tumour response criteria (TRCs) in assessment of regorafenib activity in patients with advanced gastrointestinal stromal tumour (GIST) with prior failure of imatinib and sunitinib.
  
  
  METHODS
  Twenty participants in a phase II trial received oral regorafenib (median duration 47 weeks; interquartile range (IQR) 24-88) with computed tomography (CT) imaging at baseline and every two months thereafter. Tumour response was prospectively determined on using Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, and retrospectively reassessed for comparison per RECIST 1.0, World Health Organization (WHO) and Choi criteria, using the same target lesions. Clinical benefit rate [CBR; complete or partial response (CR or PR) or stable disease (SD)≥16 weeks] and progression-free survival (PFS) were compared between various TRCs using kappa statistics. Performance of TRCs in predicting overall survival (OS) was compared by comparing OS in groups with progression-free intervals less than or greater than 20 weeks by each TRC using c-statistics.
  
  
  RESULTS
  PR was more frequent by Choi (90%) than RECIST 1.1, RECIST 1.0 and WHO (20% each), however, CBR was similar between various TRCs (overall CBR 85-90%, 95-100% agreement between all TRC pairs). PFS per RECIST 1.0 was similar to RECIST 1.1 (median 44 weeks versus 58 weeks), and shorter for WHO (median 34 weeks) and Choi (median 24 weeks). With RECIST 1.1, RECIST 1.0 and WHO, there was moderate concordance between PFS and OS (c-statistics 0.596-0.679). Choi criteria had less favourable concordance (c-statistic 0.506).
  
  
  CONCLUSIONS
  RECIST 1.1 and WHO performed somewhat better than Choi criteria as TRC for response evaluation in patients with advanced GIST after prior failure on imatinib and sunitinib.
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States. Electronic address: ashinagare@partners.org.
authors.forename: Atul B
authors.initials: AB
authors.lastname: Shinagare
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Jyothi P
authors.initials: JP
authors.lastname: Jagannathan
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Vikram
authors.initials: V
authors.lastname: Kurra
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Trinity
authors.initials: T
authors.lastname: Urban
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Judith
authors.initials: J
authors.lastname: Manola
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Edwin
authors.initials: E
authors.lastname: Choy
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: George D
authors.initials: GD
authors.lastname: Demetri
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Suzanne
authors.initials: S
authors.lastname: George
authors.affiliation: Department of Imaging, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States; Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02215, United States; Ludwig Center and Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA 02215, United States.
authors.forename: Nikhil H
authors.initials: NH
authors.lastname: Ramaiya
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides / Q000627:therapeutic use; D018572:Disease-Free Survival; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate; D007211:Indoles / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000592:standards; D010671:Phenylurea Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D010879:Piperazines / Q000627:therapeutic use; D011446:Prospective Studies; D011725:Pyridines / Q000008:administration & dosage / Q000627:therapeutic use*; D011743:Pyrimidines / Q000627:therapeutic use; D011758:Pyrroles / Q000627:therapeutic use; D012189:Retrospective Studies; D000077210:Sunitinib; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure; D014944:World Health Organization
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D007211:Indoles; D010671:Phenylurea Compounds; D010879:Piperazines; D011725:Pyridines; D011743:Pyrimidines; D011758:Pyrroles; C559147:regorafenib; D000068877:Imatinib Mesylate; D000077210:Sunitinib
keywords: Choi; Gastrointestinal stromal tumour; RECIST; Regorafenib; Tumour response criteria