title: High-dose tamoxifen treatment increases the incidence of multifocal tumor recurrences in glioblastoma patients.
abstract: BACKGROUND
  Multifocal tumor recurrences in glioblastoma patients are described in 4% - 14% of cases. Two recent studies, treating newly diagnosed glioblastoma patients with continuous high-dose tamoxifen (TAM), reported an increased incidence of multifocal tumor recurrences in 45.5% and 33% of study patients.
  
  
  METHODS
  Fifty newly diagnosed patients with glioblastoma were treated with 3 cycles of carboplatin, continuous high-dose TAM and radiotherapy. Tumor progression was determined on follow-up MRI studies at 3-month intervals and categorized as either local or multifocal.
  
  
  RESULTS
  Multifocal tumor recurrence was found in 16 (33%) out of 49 study patients. Compared to tumors which remained local, multifocal tumor recurrences were characterized by a significantly longer median time to tumor progression (41 vs. 23 weeks, Breslow test: p = 0.0123). Multifocal tumor recurrences were mainly observed after an initial response to the study treatment (81%), whereas local regrowth was more often associated with initial treatment failure, i.e. progressive disease (64%).
  
  
  CONCLUSIONS
  The association of the pattern of tumor recurrence with the type of response to TAM treatment suggests that acquired resistance to TAM might be an important contributing mechanism in the development of multifocal glioblastoma disease.
authors.affiliation: Department of Neurosurgery, Gilead Hospital, Bielefeld, Germany. PuchnerM@neurochirurgie.gilead.de
authors.forename: Maximilian J A
authors.initials: MJ
authors.lastname: Puchner
authors.forename: Alf
authors.initials: A
authors.lastname: Giese
authors.forename: Frauke
authors.initials: F
authors.lastname: Lohmann
authors.forename: Loris
authors.initials: L
authors.lastname: Cristante
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy; D002945:Cisplatin / Q000008:administration & dosage; D017322:Clinical Trials, Phase II as Topic; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D005260:Female; D005909:Glioblastoma / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D013629:Tamoxifen / Q000008:administration & dosage*
chemical_list: D013629:Tamoxifen; D002945:Cisplatin