title: Residual prostate cancer in patients treated with endocrine therapy with or without radical radiotherapy: a side study of the SPCG-7 randomized trial.
abstract: OBJECTIVE
  The Scandinavian Prostate Cancer Group-7 randomized trial demonstrated a survival benefit of combined endocrine therapy and external-beam radiotherapy over endocrine therapy alone in patients with high-risk prostate cancer. In a subset of the study population, the incidence and clinical implications of residual prostate cancer in posttreatment prostate biopsy specimens was evaluated.
  
  
  METHODS
  Biopsy specimens were obtained from 120 of 875 men in the Scandinavian Prostate Cancer Group-7 study.
  
  
  RESULTS
  Biopsies were performed at median of 45 months follow-up. In 63 patients receiving endocrine treatment only and 57 patients receiving combined treatment, residual cancer was found in 66% (n = 41) and 22% (n = 12), respectively (p < 0.0001). The vast majority of residual tumors were poorly differentiated (Gleason score ≥ 8). Endocrine therapy alone was predictive of residual prostate cancer: odds ratio 7.49 (3.18-17.7), p < 0.0001. In patients with positive vs. negative biopsy the incidences of clinical events were as follows: biochemical recurrence 74% vs. 27% (p < 0.0001), local progression 26% vs. 4.7% (p = 0.002), distant recurrence 17% vs. 9.4% (p = 0.27), clinical recurrence 36% vs. 13% (p = 0.006), cancer-specific death 19% vs. 9.7% (p = 0.025). In multivariable analysis, biochemical recurrence was significantly associated with residual cancer: hazard ratio 2.69 (1.45-4.99), p = 0.002, and endocrine therapy alone hazard ratio 3.45 (1.80-6.62), p < 0.0001.
  
  
  CONCLUSIONS
  Radiotherapy combined with hormones improved local tumor control in comparison with endocrine therapy alone. Residual prostate cancer was significantly associated with serum prostate-specific antigen recurrence, local tumor progression, clinical recurrence, and cancer-specific death in univariable analysis. Residual cancer was predictive of prostate-specific antigen recurrence in multivariable analysis.
authors.affiliation: Department of Oncology and Radiotherapy, St Olav's Hospital, Trondheim University Hospital, Trondheim, Norway. arne.solberg@stolav.no
authors.forename: Arne
authors.initials: A
authors.lastname: Solberg
authors.forename: Olav A
authors.initials: OA
authors.lastname: Haugen
authors.forename: Trond
authors.initials: T
authors.lastname: Viset
authors.forename: Anders
authors.initials: A
authors.lastname: Bergh
authors.forename: Ilker
authors.initials: I
authors.lastname: Tasdemir
authors.forename: Göran
authors.initials: G
authors.lastname: Ahlgren
authors.forename: Anders
authors.initials: A
authors.lastname: Widmark
authors.forename: Anders
authors.initials: A
authors.lastname: Angelsen
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D000813:Anilides / Q000627:therapeutic use; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001706:Biopsy; D003131:Combined Modality Therapy / Q000379:methods; D018450:Disease Progression; D005485:Flutamide / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D016729:Leuprolide / Q000627:therapeutic use; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000401:mortality / Q000473:pathology; D018365:Neoplasm, Residual; D009570:Nitriles / Q000627:therapeutic use; D016017:Odds Ratio; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy; D014105:Tosyl Compounds / Q000627:therapeutic use
chemical_list: D000726:Androgen Antagonists; D000813:Anilides; D018931:Antineoplastic Agents, Hormonal; D009570:Nitriles; D014105:Tosyl Compounds; D005485:Flutamide; C053541:bicalutamide; D017430:Prostate-Specific Antigen; D016729:Leuprolide