Residual prostate cancer in patients treated with endocrine therapy with or without radical radiotherapy: a side study of the SPCG-7 randomized trial.
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.
Solberg
Arne
A
Department of Oncology and Radiotherapy, St Olav's Hospital, Trondheim University Hospital, Trondheim, Norway. arne.solberg@stolav.no
Haugen
Olav A
OA
Viset
Trond
T
Bergh
Anders
A
Tasdemir
Ilker
I
Ahlgren
Göran
G
Widmark
Anders
A
Angelsen
Anders
A
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
D000726:Androgen Antagonists; D000813:Anilides; D018931:Antineoplastic Agents, Hormonal; D009570:Nitriles; D014105:Tosyl Compounds; D005485:Flutamide; C053541:bicalutamide; D017430:Prostate-Specific Antigen; D016729:Leuprolide