title: Analysis of the correlation between endorectal MRI response to neoadjuvant chemotherapy and biochemical recurrence in patients with high-risk localized prostate cancer.
abstract: BACKGROUND
  Intermediate end points are desirable to expedite the integration of neoadjuvant systemic therapy into the treatment strategy for high-risk localized prostate cancer. Endorectal magnetic resonance imaging at 1.5 Tesla (1.5T erMRI) response has been utilized as an end point in neoadjuvant trials but has not been correlated with clinical outcomes.
  
  
  METHODS
  Data were pooled from two trials exploring neoadjuvant chemotherapy in high-risk localized prostate cancer. Trial 1 explored docetaxel for 6 months and Trial 2 explored docetaxel plus bevacizumab for 4.5 months, both before radical prostatectomy. erMRI was done at baseline and end of chemotherapy. 1.5T erMRI response, based upon T2W sequences, was recorded. Multivariable Cox regression was undertaken to evaluate the association between clinical parameters and biochemical recurrence.
  
  
  RESULTS
  There were 53 evaluable patients in the combined analysis: 20 (33%) achieved a PSA response, 16 (27%) achieved an erMRI partial response and 24 (40%) achieved an erMRI minor response. Median follow-up was 4.2 years, and 33 of 53 evaluable (62%) patients developed biochemical recurrence. On multivariable analysis, PSA response did not correlate with biochemical recurrence (hazard ratio=0.58, 95% confidence interval (CI) 0.25-1.33) and paradoxically erMRI response was associated with a significantly shorter time to biochemical recurrence (hazard ratio=2.47, 95% CI 1.00-6.13).
  
  
  CONCLUSIONS
  Response by 1.5T erMRI does not correlate with a decreased likelihood of biochemical recurrence in patients with high-risk localized prostate cancer treated with neoadjuvant docetaxel and may be associated with inferior outcomes. These data do not support the use of 1.5T erMRI response as a primary end point in neoadjuvant chemotherapy trials.
authors.affiliation: Department of Medicine, Mount Sinai School of Medicine, Tisch Cancer Institute, New York, NY 10029, USA. Matthew.galsky@mssm.edu
authors.forename: M D
authors.initials: MD
authors.lastname: Galsky
authors.forename: W
authors.initials: W
authors.lastname: Xie
authors.forename: M
authors.initials: M
authors.lastname: Nakabayashi
authors.forename: R W
authors.initials: RW
authors.lastname: Ross
authors.forename: F M
authors.initials: FM
authors.lastname: Fennessy
authors.forename: C M
authors.initials: CM
authors.lastname: Tempany
authors.forename: T K
authors.initials: TK
authors.lastname: Choueiri
authors.forename: K
authors.initials: K
authors.lastname: Khine
authors.forename: P W
authors.initials: PW
authors.lastname: Kantoff
authors.forename: M-E
authors.initials: ME
authors.lastname: Taplin
authors.forename: W K
authors.initials: WK
authors.lastname: Oh
mesh_terms: D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000068258:Bevacizumab; D017024:Chemotherapy, Adjuvant; D017322:Clinical Trials, Phase II as Topic; D000077143:Docetaxel; D006801:Humans; D007610:Kallikreins / Q000097:blood; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D043823:Taxoids / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D043823:Taxoids; D000077143:Docetaxel; D000068258:Bevacizumab; C549870:KLK3 protein, human; D007610:Kallikreins; D017430:Prostate-Specific Antigen