Lara Franziska Stolzenbach1, Giuseppe Rosiello2, Marina Deuker3, Thomas Martin4, Sophie Knipper5, Zhe Tian4, Alberto Briganti6, Kevin C Zorn4, Fred Saad4, Felix K H Chun7, Markus Graefen5, Pierre I Karakiewicz4. 1. Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany; Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montreal Health Center, Montreal, Quebec, Canada. Electronic address: fstolzenbach@icloud.com. 2. Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montreal Health Center, Montreal, Quebec, Canada; Department of Urology and Division of Experimental Oncology, URI, Urological Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy. 3. Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montreal Health Center, Montreal, Quebec, Canada; Department of Urology, University Hospital Frankfurt, Frankfurt am Main, Germany. 4. Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montreal Health Center, Montreal, Quebec, Canada. 5. Martini-Klinik Prostate Cancer Center, University Hospital Hamburg-Eppendorf, Hamburg, Germany. 6. Department of Urology and Division of Experimental Oncology, URI, Urological Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy. 7. Department of Urology, University Hospital Frankfurt, Frankfurt am Main, Germany.
Abstract
BACKGROUND: It is unknown, whether metastatic prostate cancer (CaP) patients with intermediate life expectancy (5-10 years) should be considered for external beam radiation therapy (EBRT) to the prostate. We addressed this void. METHODS: Within the Surveillance, Epidemiology, and End Results database (2004-2016), we identified 835 M1a or M1b CaP substaged patients with prostate-specific antigen (PSA) < 20 ng/ml and with intermediate life expectancy (LE) 5 to 10 years, treated with EBRT or no EBRT. Inverse probability of treatment-weighting (IPTW), Kaplan-Meier plots and Cox-regression models (CRMs) were used. RESULTS: Overall, 179 (21.4%) patients received EBRT and 656 (78.6%) did not. EBRT rates increased from 13.9 to 23.8% (2004-2016; P= 0.04). After IPTW-adjustment, median OS was 45 vs. 35 months, in EBRT vs. no EBRT patients (P < 0.001). In IPTW-adjusted Cox-regression models, EBRT independently predicted lower overall mortality (hazard ratio [HR]: 0.7, CI 0.61-0.89; P= 0.001). After stratification according to M1 substages, EBRT was associated with lower overall mortality in M1a (HR: 0.2, CI 0.05-0.91; P= 0.03) and M1b (HR: 0.7, CI 0.55-0.88; P = 0.003) substages. CONCLUSION: EBRT was associated with lower mortality in metastatic CaP patients with low PSA and intermediate LE (5-10 years). In consequence, greater consideration for EBRT should be given in those patients. However, it is important to consider study limitations until clinical trials confirm the proposed benefit.
BACKGROUND: It is unknown, whether metastatic prostate cancer (CaP) patients with intermediate life expectancy (5-10 years) should be considered for external beam radiation therapy (EBRT) to the prostate. We addressed this void. METHODS: Within the Surveillance, Epidemiology, and End Results database (2004-2016), we identified 835 M1a or M1b CaP substaged patients with prostate-specific antigen (PSA) < 20 ng/ml and with intermediate life expectancy (LE) 5 to 10 years, treated with EBRT or no EBRT. Inverse probability of treatment-weighting (IPTW), Kaplan-Meier plots and Cox-regression models (CRMs) were used. RESULTS: Overall, 179 (21.4%) patients received EBRT and 656 (78.6%) did not. EBRT rates increased from 13.9 to 23.8% (2004-2016; P= 0.04). After IPTW-adjustment, median OS was 45 vs. 35 months, in EBRT vs. no EBRT patients (P < 0.001). In IPTW-adjusted Cox-regression models, EBRT independently predicted lower overall mortality (hazard ratio [HR]: 0.7, CI 0.61-0.89; P= 0.001). After stratification according to M1 substages, EBRT was associated with lower overall mortality in M1a (HR: 0.2, CI 0.05-0.91; P= 0.03) and M1b (HR: 0.7, CI 0.55-0.88; P = 0.003) substages. CONCLUSION: EBRT was associated with lower mortality in metastatic CaP patients with low PSA and intermediate LE (5-10 years). In consequence, greater consideration for EBRT should be given in those patients. However, it is important to consider study limitations until clinical trials confirm the proposed benefit.