Page 5 - CUA2019 Abstracts - Oncology-Prostate

2019 CUA Abstracts

MP-4.12 PSA, and PSA-nadir post-salvage cryotherapy predicted PCSS in multivari-
Examining contemporary prostate-specific antigen usage able analysis. Twelve-year freedom from CRPC was 80% (CI 73–87) and
practices in Nova Scotia using the Canadian Primary Care MFS was 78% (CI 71–85). Median time to BCR was 58 months (CI 44–79),
Sentinel Surveillance Network database with median time to ADT 101 months (CI 65–NA). Ninety-one patients
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Sandra Kim , Christie Chan , Ricardo A. Rendon , David Bell , Rodrigo (48.7%) were androgen-deprivation therapy (ADT)-free at end of followup.
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Romao , Gabriella Ilie , Mathew Grandy , Ross Mason 1 Conclusions: Salvage cryotherapy for localized radio-recurrent prostate
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1 Urology, Dalhousie University, Halifax, NS, Canada; Family Medicine, cancer can provide durable response, with PCSS and MFS of approxi-
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Dalhousie University, Halifax, NS, Canada; Community Health and mately 80% at 12 years. Salvage treatment can achieve ADT-free status in
Epidemiology, Dalhousie University, Halifax, NS, Canada selected patients and delay the need for ADT in those who subsequently
Introduction: Prostate-specific antigen (PSA) testing for prostate cancer develop systemic disease.
screening remains a controversial topic, specifically in the field of primary
care. Herein, we examined contemporary PSA usage practices in Nova MP-4.14
Scotia using the Canadian Primary Care Sentinel Surveillance Network Exosomal AR-V7 as a prognostic biomarker in patients with
(CPCSSN)-MaRNetFP database. castration-resistant prostate cancer
Methods: Information on PSA tests ordered by primary care physicians France-Hélène Joncas , Frédéric Pouliot , Fannie Morin , Mélanie
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across the province between 2006 and 2017 was collected using the Rouleau , Yves Fradet , Caroline Gilbert , Paul Toren 1,2
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CPCSSN-MaRNetFP Nova Scotia database using cross-sectional data. The 1 Department of Surgery, Université Laval, Québec City, QC, Canada;
database includes records from 58 229 males. Descriptive analyses were 2 Division of Oncology, CHU de Québec Research Centre, Québec City,
used to examine number of PSA tests performed by patient age. QC, Canada; Division of Infectious and Immune Diseases, CHU de
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Results: Reviewed records from the Nova Scotia CPCSSN-MaRNetFP Québec Research Centre, Québec City, QC, Canada; Department of
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database indicate that 15 709 patients had at least one PSA tests ordered Microbiology and Immunology, Université Laval, Québec City, QC, Canada
between 2006 and 2017 and that in total, 67 582 PSA tests were ordered This work was supported by a Canadian Urological Association
by primary care physicians in that time period. Of these, 19 651 (29.1%) Scholarship Foundation-Astellas grant.
PSA tests were linked to patients who received a diagnosis of prostatic Introduction: The development of phenotypic biomarkers to aid in the
pathology (e.g., prostate cancer, benign prostatic hypertrophy, or prostati- selection of treatment for patients with castration-resistant prostate cancer
tis). The remaining 47 931 (70.9%) of PSA tests ordered were not linked to (CRPC) is an important priority. Plasma exosomes have excellent potential
any diagnosis of prostatic pathology. Among the PSA tests performed with- as real-time biomarkers to characterize the tumour since they are easily
out a diagnosis of prostatic disease, 6692 (13.9%) were ordered for men accessible in the blood, and contain DNA, RNA, and protein. In this study,
younger than 50 and 8701 (18.2%) were ordered for men older than 70. we investigate plasma exosomes as biomarkers in patients with CRPC.
Conclusions: The majority of PSA tests performed in Nova Scotia are on Methods: We investigated plasma extracellular vesicles (EVs) in patients
patients between the ages of 50 and 70, although a significant proportion with CRPC. EVs were isolated using both precipitation and ultracentrifu-
of tests are performed outside of these guideline-based age ranges. Further gation methods; physical characterization was performed using dynamic
analysis of this data will be aimed at identifying factors associated with light scattering, acetylcholinesterase activity, and iodixanol gradients.
appropriate and inappropriate PSA assessment use to optimize usage of Exosomal mRNA was quantified using digital droplet polymerase chain
valuable healthcare resources. reaction (PCR) for KLK3 and AR-V7 genes. Serum sex steroids were mea-
This paper has a figure, which may be viewed online at: sured using liquid chromatography tandem mass spectroscopy.
https://2019.cua.events/webapp/lecture/122 Results: No significant differences in physical properties of EVs were
observed in CRPC patients compared to controls with localized or hor-
MP-4.13 mone-sensitive prostate cancer. Velocity gradients identified that PSMA-
Tumour control outcomes of salvage cryotherapy for radio- positive exosomes occupied a specific fraction of isolated EVs. A total
recurrent prostate cancer at median 12 years’ followup of 37 patients had mRNA analyzed from plasma exosomes. Detectable
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Shiva M. Nair , Max Peters , Haider Abed , Jochem van der Voort van exosomal KLK3, the gene coding for prostate-specific antigen (PSA), corre-
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Zyp , Marieke van Son , Joseph Chin 1 sponded with higher concomitant serum PSA measurements, as expected
1 Division of Urology, Department of Surgery, University of Western (mean 145.4 ng/mL vs 17.1 ng/mL; p=0.02). Further, detectable levels of
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Ontario, London, ON, Canada; Department of Radiotherapy, University the androgen receptor splice variant AR-V7 was associated with a shorter
Medical Centre Utrecht, Utrecht, Netherland time to progression (mean 15.9 vs. 33.5; log-rank p=0.02). Further, detect-
Introduction: Local prostate cancer recurrences after primary radiotherapy able exosomal ARv7 was significantly associated with testosterone levels
can occur. Salvage therapies can defer the use of subsequent non-curative below the lower limit of quantification (<0.1 nM).
systemic therapies, which have significant side effects. The aim of the Conclusions: Our results highlight the utility of plasma exosomes as
study is to examine long-term oncological results of a large cohort of phenotypic biomarkers and confirm that exosomal AR-V7 status is sig-
salvage cryotherapy patients. nificantly associated with patient prognosis in patients with advanced
Methods: Patients treated with salvage cryotherapy between March 1995 prostate cancer.
and September 2004 were included. Patients had histological confirma-
tion of local recurrence. Metastatic screen with computed tomography MP-4.15
(CT) and radionucleotide bone scan was negative. Pre-salvage clinical Abiraterone vs. docetaxel for metastatic hormone-sensitive prostate
data was collected to predict oncological outcomes. Kaplan-Meier analy- cancer: A Markov microsimulation model
sis was performed to assess overall survival (OS), prostate cancer-specific Amanda Hird , Douglas C. Cheung , Diana E. Magee , Rano Matta ,
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survival (PCSS), metastases-free survival (MFS), and castrate-resistant pros- Robert K. Nam , Girish S. Kulkarni 2
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tate cancer (CRPC). The Pheonix definition was used for biochemical 1 Urology, Sunnybrook Health Sciences Centre, University of Toronto,
recurrence (BCR). Cox regression was used to assess predictive factors Toronto, ON, Canada; Urology, Toronto General Hospital, University of
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for OS, PCSS, CRPC, and MFS. Toronto, Toronto, ON, Canada
Results: A total of 187 patients were treated with salvage cryotherapy. Introduction: In the setting of metastatic castrate-sensitive prostate cancer
Median followup was 149 months (12 years). Median age before salvage (mCSPC), androgen-deprivation therapy (ADT) has traditionally been the
was 71 years (interquartile range [IQR] 66–74), median prostate-specific standard of care; however, the introduction of early docetaxel chemo-
antigen (PSA) pre-salvage 11 ng/ml (IQR 7.8–18.7). Twelve-year OS was therapy (DC) and anti-androgen agents (abiraterone with prednisone [AA])
56% (confidence interval [CI] 49–64). Pre-salvage age and PSA nadir have resulted in significant improvements in overall survival (OS). While
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post-salvage predicted overall mortality. Twelve-year PCSS was 81% (CI these two alternative regimens have shown to be efficacious, they have
75–88). Pre-radiation Gleason score 8–10 and stage (T3a–T4), pre-salvage
S108 CUAJ • June 2019 • Volume 13, Issue 6(Suppl5)