title: The magnitude of early castration-induced primary tumour regression in prostate cancer does not predict clinical outcome.
abstract: BACKGROUND
  This study was designed to test whether early castration-induced short-term cellular changes in primary prostate tumours could predict clinical outcome in advanced disease.
  
  
  METHODS
  Biopsies from 83 patients obtained before and within two weeks after surgical castration were investigated. Tumour epithelial cell apoptosis, proliferation, and prostate specific antigen (PSA) levels were quantified using immunohistochemistry, laser capture micro-dissection, and real time RT-PCR. Cellular effects were related to changes in serum PSA levels and clinical outcome.
  
  
  RESULTS
  Decreased proliferation and PSA mRNA levels, and increased apoptosis were observed in most tumours. These early cellular responses were not correlated to each other and did not predict serum PSA response or cancer-specific survival. A nadir PSA level below 1 ng/ml predicted a longer cancer-specific survival after castration therapy.
  
  
  CONCLUSIONS
  Castration therapy causes primary tumour regression in most patients with advanced prostate cancer, but these primary tumour effects are not predictive for systemic disease control. Studies of early changes in metastases during hormonal therapy will probably give more predictive information for clinical outcome than further studies in primary tumours.
authors.affiliation: Department of Medical Biosciences, Pathology, Umeå University, Umeå, Sweden. nina.ohlson@medbio.umu.se
authors.forename: Nina
authors.initials: N
authors.lastname: Ohlson
authors.forename: Anders
authors.initials: A
authors.lastname: Bergh
authors.forename: Katarina
authors.initials: K
authors.lastname: Nygren
authors.forename: Pär
authors.initials: P
authors.lastname: Stattin
authors.forename: Pernilla
authors.initials: P
authors.lastname: Wikström
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D017209:Apoptosis; D001706:Biopsy; D016009:Chi-Square Distribution; D003131:Combined Modality Therapy; D018450:Disease Progression; D005485:Flutamide / Q000627:therapeutic use*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009367:Neoplasm Staging; D009919:Orchiectomy; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000628:therapy*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D016896:Treatment Outcome
chemical_list: D000726:Androgen Antagonists; D005485:Flutamide; D017430:Prostate-Specific Antigen