Page 56 - CUA 2020_Onco_Prostate

2020 CUA Abstracts

MP-10.7
The comparative outcomes of radical prostatectomy vs.
radiotherapy for non-metastatic prostate cancer: A longitudinal,
population-based analysis
2,3
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Justin Oake , Benjamin Shiff , Oksana Harasemiw , Navdeep Tangri 2,3,4 ,
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Thomas W. Ferguson , Bimal Bhindi , Jeffery W. Saranchuk , Rahul K.
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Bansal , Darrel E. Drachenberg , Jasmir (Jay) G. Nayak 1
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1 Section of Urology, University of Manitoba, Winnipeg, MB,
Canada; Chronic Disease Innovation Centre, Seven Oaks General
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Hospital, Winnipeg, MB, Canada; Department of Internal Medicine,
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University of Manitoba, Winnipeg, MB, Canada; Department of
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Community Health Sciences, University of Manitoba, Winnipeg, MB,
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Canada; Section of Urology, University of Calgary, Calgary, AB, Canada
Introduction: The comparative effectiveness of radical prostatectomy (RP)
vs. radiation therapy (RT) for prostate cancer remains a largely debated
topic. Using a provincial, population-based, linked dataset from an equal-
access, universal healthcare system, we sought to compare outcomes
among patients treated with either RT or RP for non-metastatic prostate
cancer.
Methods: We performed a retrospective cohort study by linking several
administrative datasets to identify patients who were diagnosed with
prostate cancer from 2004–2016 in Manitoba, Canada, and who were
subsequently treated with either RP or RT. Cox proportional hazard mod-
els with inverse probability of treatment weighting (IPTW) were used to
compare rates of all-cause mortality, as well as prostate cancer-specific MP-10.8. Fig. 1. Disease-free survival.
mortality (PCSM) between patients who underwent RP vs. RT.
Results: During the study period, 2540 patients underwent RP and 1895 prior clinical failure, was correlated with disease status at 10–15 years.
underwent RT for prostate cancer. Unadjusted overall survival (OS) was Kaplan-Meier analysis was carried out using clinical failure (local, distant,
higher for RP vs. RT (five-year OS 95.52% for RP compared with 84.55% regional, or biochemical triggering salvage) as endpoints for each of four
for RT; p<0.0001). In IPTW-adjusted Cox regression analysis, compared PSA categories: PSA <0.2 ng/ml, PSA >0.2 to <0.5, PSA >0.5 to <1.0,
to patients in the RP groups, patients in the RT group had an increased and PSA >1.0 ng/ml. Results were compared to three independent valida-
rate of all-cause mortality (hazard ratio [HR] 1.93; 95% confidence inter- tion cohorts: low-risk (n=366: Australia), intermediate-risk (n=221: MD
val [CI] 1.65–2.26; p<0.0001) and PCSM (HR 3.98; 95% CI 2.89–5.49; Anderson Phase 2 trial), and high-risk (n=160: AscendeRT Phase 3 trial
p<0.0001). BT arm).
Conclusions: RT was associated with lower OS and higher PCSM rates Results: Most (77.1%) patients had a PSA<0.2 ng/ml at four years. Kaplan-
compared with RP. These findings highlight the importance of compara- Meier analysis showed 98.7% free of recurrence at 10 years (95% confi-
tive effectiveness research to identify treatment disparities and warrant dence interval [CI] 98.3–99.0) and 96.1% at 15 years (95% CI 94.8–97.2).
further investigation. Successive PSA categories were associated with diminished disease-free
rates at 10 and 15 years (Fig. 1). PSA range was strongly associated
with treatment success (p<0.0005). Median PSA at 10 (n=4864, readings)
MP-10.8 and 15 years (n=1137) was 0.01 ng/ml. For the three validation cohorts,
Biochemical definition of cure after low dose rate prostate PSA<0.2 ng/ml at four years was associated with 99.0%, 99.4%, and
brachytherapy 96.7% freedom from failure at 10 years, respectively.
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Juanita Crook , Chad Tang , Howard Thames , Pierre Blanchard , Jeremiah Conclusions: As over 80% of patients achieve a PSA <0.2 ng/ml at four
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Sanders , Jay Ciezki , Mira Keyes , Gregory Merrick , Charles Catton , years post-LDR BT, and this is associated with 97–99% being disease-free
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Hamid Raziee , Richard Stock , Frank J Sullivan , Jeremy Millar , Mitch beyond 10 years, we suggest that this biochemical definition of cure be
Anscher , Steven Frank 2 adopted for LDR brachytherapy patients with ≥4 years’ followup.
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1 Radiation Oncology, BC Cancer, Kelowna, BC, Canada; Radiation
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Oncology, MD Anderson, Houston, TX, United States; Radiation MP-10.10
Oncology, Case Western Reserve University, Cleveland, OH, United
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States; Radiation Oncology, BC Cancer, Vancouver, BC, Canada; Does salvage whole gland ablation therapy confer survival
5 Radiation Oncology, Schiffler Cancer Center, Wheeling, WV, United advantage to patients who failed primary radiotherapy for
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States; Radiation Oncology, University Health Network, Toronto, ON, prostate cancer? 2 1 2
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Canada; Radiation Oncology, Mt Sinai School of Medicine, New York, Shiva M. Nair , Andrew Warner , Arnon Lavi , George B. Rodrigues , L.K.
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NY, United States; Galway Clinic, National University of Ireland, Galway, Joseph Chin
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Ireland; Alfred Health, Melbourne, Australia Departments of Urology and Oncology, Schulich School of Medicine
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Introduction: The incorporation of brachytherapy into the radiation man- and Dentistry, Western University, London, ON, Canada; Department of
agement of prostate cancer is associated with extremely low and stable Radiation Oncology, Schulich School of Medicine and Dentistry, Western
prostate-specific antigen (PSA) values. Prior consensus has defined failure University, London, ON, Canada
after radiation with high specificity, but not cure. We sought to identify a Support: Pan-Canadian Prostate Cancer Risk Stratification (ProCaRS)
PSA threshold value, at an intermediate followup time, associated with Introduction: Men experiencing prostate cancer recurrence after radio-
cure as defined by long term (10–15-year) freedom from prostate cancer. therapy usually progress to systemic therapies, most often with androgen
Methods: We analyzed prospectively collected outcome data from seven deprivation therapy (ADT). Selected men may be candidates for local sal-
institutions for 14 220 patients with localized prostate cancer treated with vage therapy, avoiding or at least delaying ADT. We compared long-term
low dose rate (LDR) brachytherapy (BT) either alone (n=8552: 61%) or in outcomes of post-radiation-salvage cryoablation (sCT) and high-intensity
combination with external beam radiotherapy (n=1175: 8%), androgen focused ultrasound (sHIFU) vs. standard of care (SOC) without local sal-
deprivation (n=3165:22%) or both (n=1,328: 9%); 42% were low-risk, vage therapy in a large radiation therapy database.
50% intermediate-, and 8% high-risk. PSA measured at four years (range Methods: Men undergoing ablation for localized radio-recurrent prostate
3.5–4.5) in 8746 patients with minimum 3.5-year PSA followup, without cancer at Western University between 1995 and 2018 were identified. The
S140 CUAJ • June 2020 • Volume 14, Issue 6(Suppl2)