ASCO 2017: Survival impact of initial local therapy selection for men under 60 with high risk prostate cancer

Chicago, IL (UroToday.com) The impact of initial local therapy selection on survival for high-risk prostate cancer (PCa) patients remains uncertain, particularly in younger men who in general have an appropriate life-expectancy at the time of prostate cancer diagnosis. Dr. Adeel Kaiser and colleagues presented their results of a study assessing the impact of initial local therapy selection for men under 60 with high-risk prostate cancer at the prostate cancer poster sessions at the 2017 ASCO annual meeting. To minimize the competing risk of death, the authors chose a younger cohort to assess the impact of initial local therapy on survival. 

For this study, the authors utilized the National Cancer Database to evaluate the overall survival (OS) of men under 60 with high risk PCa receiving either radiation therapy or radical prostatectomy (RP). All men in this age group were treated between 2004 and 2013, harbored cN0M0 disease, and presented with Gleason Scores (GS) 8-10 disease. The radiotherapy group included patients who received external beam radiation (EBRT) alone or EBRT in combination with brachytherapy. A total of 16,944 patients were included, of which 12,155 underwent RP and 4,789 received radiotherapy as initial therapy. Eighty-three percent of radiotherapy patients received hormonal therapy, and the median dose was 77.4 Gy. In the RP group, 17.2% of patients received postoperative radiation, and 87% of these cases received a dose exceeding 64.80 Gy. Over a median follow-up of 50 months (range: 0 - 131 months), using Cox proportional hazard modelling, RP was associated with improved OS in comparison to radiotherapy (HR 0.52; 95%CI 0.47-0.58). The estimated 8-year OS (±1 standard error of the estimate) was 85.1±0.7% and 74.9±0.7%, after RP and radiotherapy, respectively. This benefit remained present when adjusting for age, year of treatment, race, comorbidity score, GS, T stage, hormonal therapy, chemotherapy, form of radiation, PSA, or insurance status. The strength of the study is the large sample size and rigorous methodology employed by the authors. Potential limitations include the retrospective nature of the study and the lack of prostate cancer specific mortality outcomes.

The authors concluded that compared to radiotherapy, initial treatment of men under 60 with high-risk prostate cancer with RP results in a large, statistically significant improvement in overall survival that remains consistent over time and remains significant in a multivariable model adjusting for known prognostic variables. In young patients, surgical treatment of high-risk, localized disease remains the current standard of care.

Presented By: Adeel Kaiser, MD, University of Maryland School of Medicine, Baltimore, MD, USA

Co-Authors: Soren Bentzen, Minhaj Siddiqui, Michael J Naslund, Young Kwok, Pradip P. Amin, Zeljko Vujaskovic, Mark Vikas Mishra, Shahed Nicolas Badiyan

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
Twitter: @zklaassen_md

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 - Chicago, Illinois, USA