title: Chemotherapy for malignant gliomas based on histoculture drug response assay : a pilot study.
abstract: OBJECTIVE
  The Histoculture Drug Response Assay (HDRA), which measures chemosensitivity using minced tumor tissue on drug-soaked gelfoam, has been expected to overcome the limitations of in vitro chemosensitivity test in part. We analyzed interim results of HDRA in malignant gliomas to see if the test can deserve further clinical trials.
  
  
  METHODS
  Thirty-three patients with malignant gliomas were operated and their tumor samples were examined for the chemosensitivity to 10 chosen drugs by HDRA. The most sensitive chemotherapy regimen among those pre-established was chosen based on the number of sensitive drugs or total inhibition rate (IR) of the regimen. The response was evaluated by 3 month magnetic resonance image.
  
  
  RESULTS
  Among 13 patients who underwent total resection of the tumor, 12 showed no evidence of disease and one patient revealed progression. The response rate in 20 patients with residual tumors was 55% (3 complete and 8 partial responses). HDRA sensitivity at the cut-off value of more than one sensitive drug in the applied regimen showed a sensitivity of 100%, specificity of 60% and predictability of 70%. Another cut-off value of >80% of total IR revealed a sensitivity of 100%, specificity of 69%, and predictability of 80%. For 12 newly diagnosed glioblastoma patients, median progression-free survival of the HDRA sensitive group was 21 months, while that of the non-sensitive group was 6 months (p=0.07).
  
  
  CONCLUSIONS
  HDRA for malignant glioma was inferred as a feasible method to predict the chemotherapy response. We are encouraged to launch phase 2 clinical trial with chemosensitivity on HDRA.
authors.affiliation: Department of Neuro-Oncology Clinic, National Cancer Center, Goyang, Korea.
authors.forename: Ho-Shin
authors.initials: HS
authors.lastname: Gwak
authors.forename: Hyeon Jin
authors.initials: HJ
authors.lastname: Park
authors.forename: Heon
authors.initials: H
authors.lastname: Yoo
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Youn
authors.forename: Chang Hun
authors.initials: CH
authors.lastname: Rhee
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee