title: Prognosis of patients with multifocal glioblastoma: a case-control study.
abstract: OBJECTIVE
  The prognosis of patients with glioblastoma who present with multifocal disease is not well documented. The objective of this study was to determine whether multifocal disease on initial presentation is associated with worse survival.
  
  
  METHODS
  The authors retrospectively reviewed records of 368 patients with newly diagnosed glioblastoma and identified 47 patients with multifocal tumors. Each patient with a multifocal tumor was then matched with a patient with a solitary glioblastoma on the basis of age, Karnofsky Performance Scale (KPS) score, and extent of resection, using a propensity score matching methodology. Radiation and temozolomide treatments were also well matched between the 2 cohorts. Kaplan-Meier estimates and log-rank tests were used to compare patient survival.
  
  
  RESULTS
  The incidence of multifocal tumors was 12.8% (47/368). The median age of patients with multifocal tumors was 61 years, 76.6% had KPS scores ≥ 70, and 87.2% underwent either a biopsy or partial resection of their tumors. The 47 patients with multifocal tumors were almost perfectly matched on the basis of age (p = 0.97), extent of resection (p = 1.0), and KPS score (p = 0.80) compared with 47 patients with a solitary glioblastoma. Age (>65 years), partial resection or biopsy, and low KPS score (<70) were associated with worse median survival within the multifocal group. In the multifocal group, 19 patients experienced tumor progression on postradiation therapy MRI, compared with 11 patients (26.8%) with tumor progression in the unifocal group (p = 0.08). Patients with multifocal tumors experienced a significantly shorter median overall survival of 6 months (95% CI 4-10 months), compared with the 11-month median survival (95% CI 10-19 months) of the matched solitary glioblastoma group (p = 0.02, log-rank test). Two-year survival rates were 4.3% for patients with multifocal tumors and 29.0% for the unifocal cohort. Patients with newly diagnosed multifocal tumors were found to have an almost 2-fold increase in the hazard of death compared with patients with solitary glioblastoma (hazard ratio 1.8, 95% CI 1.1-3.1; p = 0.02). Tumor samples were analyzed for expression of phosphorylated mitogen-activated protein kinase, phosphatase and tensin homolog, O(6)-methylguanine-DNA methyltransferase, laminin β1 and β2, as well as epidermal growth factor receptor amplification, and no significant differences in expression profile between the multifocal and solitary glioblastoma groups was found.
  
  
  CONCLUSIONS
  Patients with newly diagnosed multifocal glioblastoma on presentation experience significantly worse survival than patients with solitary glioblastoma. Patients with multifocal tumors continue to pose a therapeutic challenge in the temozolomide era and magnify the challenges faced while treating patients with malignant gliomas.
authors.affiliation: Center for Neurosurgical Outcomes Research, Maxine Dunitz Neurosurgical Institute, Department of Neurosurgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA. chirag.patil@cshs.org
authors.forename: Chirag G
authors.initials: CG
authors.lastname: Patil
authors.forename: Anthony
authors.initials: A
authors.lastname: Yi
authors.forename: Adam
authors.initials: A
authors.lastname: Elramsisy
authors.forename: Jethro
authors.initials: J
authors.lastname: Hu
authors.forename: Debraj
authors.initials: D
authors.lastname: Mukherjee
authors.forename: Dwain K
authors.initials: DK
authors.lastname: Irvin
authors.forename: John S
authors.initials: JS
authors.lastname: Yu
authors.forename: Serguei I
authors.initials: SI
authors.lastname: Bannykh
authors.forename: Keith L
authors.initials: KL
authors.lastname: Black
authors.forename: Miriam
authors.initials: M
authors.lastname: Nuño
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D016022:Case-Control Studies; D015331:Cohort Studies; D003131:Combined Modality Therapy; D003606:Dacarbazine / Q000031:analogs & derivatives / Q000627:therapeutic use; D005909:Glioblastoma / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D019635:Neurosurgical Procedures; D011379:Prognosis; D011878:Radiotherapy; D012189:Retrospective Studies; D015996:Survival Rate; D000077204:Temozolomide; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D003606:Dacarbazine; D000077204:Temozolomide