In high-risk prostate cancer (PCa), no study with observation times beyond 10 yr has demonstrated survival improvement after addition of prostatic radiotherapy (RAD) to endocrine treatment (ET) alone.
To compare mortality rates in patients receiving ET alone versus ET + RAD.
Design, settings, and participants
From 1996 to 2002, 875 Scandinavian patients with high-risk (90%) or intermediate PCa were randomized to ET or ET + RAD (The Scandinavian Prostate Cancer Group-7). After 3 mo with total androgen blockade in all patients, all individuals continued lifelong antiandrogen monotherapy. Those randomized to ET + RAD started prostate radiotherapy (70 Gy) at 3 mo.
Outcome, measurements and statistical analysis
PCa-specific 15-yr mortality represented the primary endpoint. Assessment of the combination treatment effect and prognostic factors was performed in competing risk analyses and Cox proportional-hazard models.
RAD added to ET.
Results and limitations
With a median observation time of 12 yr, the 15-yr PCa-specific mortality rates were 34% (95% confidence interval, 29–39%) and 17% (95% confidence interval, 13–22%) in the ET and ET + RAD arms respectively (p < 0.001). Compared with the ET arm, the median overall survival in the ET + RAD arm was prolonged by 2.4 yr. Treatment with ET alone, age ≥65 yr and increasing histology grade independently increased the risk of PCa-specific and overall mortality. Limitations include nonformal evaluation of comorbidity, the inability to calculate progression-free survival, and lack of information about salvage therapy and toxicity.
In patients with nonmetastatic locally advanced or aggressive PCa, ET + RAD reduces the absolute risk of PCa-specific death by 17% at 15 yr compared with ET alone; the comparable 15-yr PCa-specific mortality rates being 17% and 34%. The results warrant a phase 3 study comparing ET + RAD with radical prostatectomy in high-risk PCa.
Adding prostatic therapy to lifelong antiandrogen therapy halves the absolute risk of death from prostate cancer from 34% to 17% 15 yr after diagnosis.
Keywords: Antiandrogen monotherapy, High-risk prostate cancer, Radiotherapy, Mortality.
a Oslo University Hospital, National Advisory Unit on Late Effects after Cancer Treatment, Oslo University Hospital, Oslo, Norway
b Cancer Registry of Norway, University of Oslo, Oslo, Norway
c Faculty of Medicine, University of Oslo, Oslo, Norway
d Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden
e Department of Oncology, Ålesund Hospital, Ålesund, Norway
f Urology Clinical Center, Trondheim, Norway
g The Cancer Clinic, St. Olavs University Hospital, Trondheim, Norway
h Department of Urology, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg. Gothenburg, Sweden
i Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
j Department of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden
Corresponding author. Oslo University Hospital, Radiumhospitalet, Postboks 4953 Nydalen, Oslo 0424, Norway. Tel. +47 22934700; Fax: +47 22934553.
© 2016 European Association of Urology, Published by Elsevier B.V.