Radiation Oncology/RTOG Trials/8307



RTOG 83-07 (PROSTATE)

  • Title: Phase II Megestrol Acetate vs Diethylstilbestrol Adjuvant to Radiotherapy for Locally Advanced Stage B/C Carcinoma of the Prostate
  • Objectives:
    • (1) Evaluate the relative effectiveness and toxicity of megestrol acetate versus diethylstilbestrol as pre-adjuvants to radiotherapy; the principal endpoints are tumor clearance rates and serum testosterone levels.
    • (2) Compare the two treatment options with respect to local-regional control, disease-free interval, and survival.
    • (3) Assess the effect of both treatments on sexual function.
  • Protocol
    • Arm 1: Megestrol x 2 months followed by 65-70 Gy EBRT + Megestrol
    • Arm 2: Diethylstilbestrol x 2 months followed by 65-70 Gy EBRT + Diethylstilbestrol
  • Eligibility: Stage B2 or C, LN+ ok if below aortic bifurcation, M0
  • Enrolled: 203 patients
  • Conclusion:
    • PMID 7721614 -- Phase II trial of hormonal cytoreduction with megestrol and diethylstilbestrol in conjunction with radiotherapy for carcinoma of the prostate: outcome results of RTOG 83-07. (Pilepich MV, IJRBOP 1995). Conclusion: The results of the study indicate comparable efficacy (using tumor clearance as an end point) of DES and Megestrol. Although DES appears more effective in suppressing testosterone, it is also associated with a higher incidence of drug-related toxicity.
  • Publications:
    • PMID 10837944 -- Predicting long-term survival, and the need for hormonal therapy: a meta-analysis of RTOG prostate cancer trials. (Roach M, IJRBOP 2000). Conclusion: Based on this meta-analysis of RTOG trials, subsets of patients can be identified who either do not appear to benefit from the use of hormonal therapy, benefit from short-term hormonal therapy, or who benefit only from long-term hormonal therapy. These observations should be confirmed by prospective randomized trials before they can be considered conclusive. In the meantime, however, these observations provide rational guidelines for deciding who should receive hormonal therapy and for how long.
    • PMID 7591889 -- Correlation of survival with quantitative tissue staining of prostate specific acid phosphatase in patients with prostate carcinoma by using microscopic image analysis: a preliminary report of correlative studies on RTOG protocols 75-06, 77-06, and 83-07. (Zhou R, IJRBOP 1995). Conclusion: Quantitative image analysis of the IPSAP stain predicts survival in patients treated with external beam radiotherapy with and without prior hormonal therapy.
    • PMID 2646266 -- Hormonal cytoreduction in locally advanced carcinoma of the prostate treated with definitive radiotherapy: preliminary results of RTOG 83-07. (Pilepich MV, IJRBOP 1989). Conclusion: The results of the study indicate comparable efficacy (using tumor clearance as an end-point) of DES and Megestrol. While DES appears more effective in suppressing testosterone it is also associated with a higher incidence of toxicity. The cytoreduction (using either DES, Megestrol, or an alternative regimen) concept remains to be tested in a Phase III study comparing it to radiotherapy alone.