Shawn Dason

Dr. Shawn Dason


Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2011 in Canadian Urological Association Journal
Verified
Journal Article
Closed access
SDShawn Dason
Shawn Dason
JDJeyapandy T. Dason
Jeyapandy T. Dason
Anil KapoorAnil Kapoor
Anil Kapoor
CUAJ is the only indexed, peer-reviewed journal endorsed and supported by the Canadian Urological Association.

1 June 2012 in Clinical Radiology
Verified
Journal Article
Closed access
MDM D Dilauro
M D Dilauro
SDShawn Dason
Shawn Dason
SAS. Athreya
S. Athreya

1 June 2013 in Current Oncology
Verified
Journal Article
Open access
SDShawn Dason
Shawn Dason
CAC. Allard
C. Allard
ASA. Sheridan–Jonah
A. Sheridan–Jonah
JGJ. Gill
J. Gill
HJH. Jamshaid
H. Jamshaid
Anil KapoorAnil Kapoor
Anil Kapoor
Introduction: Collecting duct carcinoma (CDC) is a rare, aggressive form of renal carcinoma that presents at an advanced stage and has a poor prognosis. Little is known concerning the optimal management of CDC. We present the results of a systematic review addressing the management of CDC and the McMaster University CDC series. Methods: The MEDLINE, Cochrane Library, and EMBASE databases and conference proceedings were searched to identify studies relating to the management of CDC. Included studies reported on a minimum of 10 subjects receiving a single intervention. Series in which an evaluation of therapeutic effectiveness was not possible were excluded. The McMaster University (Hamilton, Ontario) series of 6 cases of CDC were retrospectively reviewed. Results: We identified 3 studies relevant to the management of CDC that included a total of 72 patients. A gemcitabine–cisplatin or –carboplatin regimen resulted in a 26% objective response rate in 23 patients with metastatic CDC. Two additional studies indicated that 49 patients treated with immunotherapy achieved no response. In the McMaster series, cytoreductive nephrectomy was performed in 4 of 6 patients. In 2 patients, MVAC therapy (methotrexate–vinblastine–doxorubicin–cisplatin) achieved no response. No significant therapeutic complications occurred, but survival was poor (median: 11 months; range: 10–33 months). Conclusions: Our review and clinical experience suggest that the current standard of care for metastatic CDC is a gemcitabine–cisplatin regimen.

20 February 2017 in Canadian Urological Association Journal
Verified
Journal Article
Open access
PDF file
NWNathan Colin Wong
Nathan Colin Wong
SDShawn Dason
Shawn Dason
RBRahul K. Bansal
Rahul K. Bansal
TDTimothy O. Davies
Timothy O. Davies
LBLuis H. Braga
Luis H. Braga
Introduction: Penile fractures have classically been thought to require immediate surgical intervention; however, recent series have described acceptable outcomes with delayed repair. In this systematic review, we compared complication rates between immediate and delayed repair of penile fractures.Methods: A systematic search of MEDLINE, Embase, CENTRAL, and Web of Science was performed with predefined search terms between 1974 and 2015. Titles and abstracts were screened prior to full-text review and quality appraisal by two independent investigators. Abstracted outcomes included postoperative erectile dysfunction (ED), tunical scar formation, and penile curvature. Only studies reporting a direct comparison of complications following immediate (24 hours) repair of penile fractures were included.Results: A total of 12 studies met inclusion criteria. All were retrospective, observational studies of low or moderate methodological quality. Of the reported 502 patients, 391 underwent immediate repair and 111 delayed repair. In the immediate repair group, the percent of patients with postoperative ED, tunical scars, and curvature were 6.6%, 5.4%, and 1.8%, respectively, while in the delayed group, the rates of ED, tunical scars, and curvature were 4.5% across the board. Rates of ED and tunical scar formation following immediate compared to delayed repair trended towards favouring immediate repair, but did not differ significantly, while rates of curvature significantly favoured immediate repair. However, cases of curvature were typically reported as mild and none affected sexual functioning.Conclusions: In this systematic review, we demonstrated that ED and tunical scar formation rates between immediate and delayed repair of penile fractures were statistically similar, while immediate repair had a lower rate of penile curvature. Although this suggests that a brief delay in repair may be acceptable in select patients, the results should be interpreted with caution, as the included studies were of low or moderate methodological quality. Most importantly, this review highlights the deficiencies in the current penile fracture literature, setting the stage to improve the quality of future studies.

8 February 2013 in Clinical Proteomics
Verified
Journal Article
Open access
PDF file
CCChan-Kyung J Cho
Chan-Kyung J Cho
ADAndrei Drabovich
Andrei Drabovich
GKGeorge S Karagiannis
George S Karagiannis
EMEduardo Martínez-Morillo
Eduardo Martínez-Morillo
SDShawn Dason
Shawn Dason
EDEleftherios P Diamandis
Eleftherios P Diamandis
Background: Down syndrome (DS), caused by an extra copy of chromosome 21, affects 1 in 750 live births and is characterized by cognitive impairment and a constellation of congenital defects. Currently, little is known about the molecular pathogenesis and no direct genotype-phenotype relationship has yet been confirmed. Since DS amniocytes are expected to have a distinct biological behaviour compared to normal amniocytes, we hypothesize that relative quantification of proteins produced from trisomy and euploid (chromosomally normal) amniocytes will reveal dysregulated molecular pathways. Results: Chromosomally normal- and Trisomy 21-amniocytes were quantitatively analyzed by using Stable Isotope Labeling of Amino acids in Cell culture and tandem mass spectrometry. A total of 4919 unique proteins were identified from the supernatant and cell lysate proteome. More specifically, 4548 unique proteins were identified from the lysate, and 91% of these proteins were quantified based on MS/MS spectra ratios of peptides containing isotope-labeled amino acids. A total of 904 proteins showed significant differential expression and were involved in 25 molecular pathways, each containing a minimum of 16 proteins. Sixty of these proteins consistently showed aberrant expression from trisomy 21 affected amniocytes, indicating their potential role in DS pathogenesis. Nine proteins were analyzed with a multiplex selected reaction monitoring assay in an independent set of Trisomy 21-amniocyte samples and two of them (SOD1 and NES) showed a consistent differential expression. Conclusions: The most extensive proteome of amniocytes and amniotic fluid has been generated and differentially expressed proteins from amniocytes with Trisomy 21 revealed molecular pathways that seem to be most significantly affected by the presence of an extra copy of chromosome 21.

24 November 2014 in Canadian Urological Association Journal
Verified
Journal Article
Open access
PDF file
Anil KapoorAnil Kapoor
Anil Kapoor
SDShawn Dason
Shawn Dason
CAChristopher B. Allard
Christopher B. Allard
BSBobby Shayegan
Bobby Shayegan
LLLouis Lacombe
Louis Lacombe
WKWassim Kassouf
Wassim Kassouf
Introduction: Radical nephroureterectomy for upper tract urothelial carcinoma (UTUC) must include some form of distal ureter management to avoid high rates of tumour recurrence. It is uncertain which distal ureter management technique has the best oncologic outcomes. To determine which distal ureter management technique resulted in the lowest tumour recurrence rate, we analyzed a multiinstitutional Canadian radical nephroureterectomy database.Methods: We retrospectively analyzed patients who underwent radical nephroureterectomy with distal ureter management for UTUC between January 1990 and June 2010 at 10 Canadian tertiary hospitals. Distal ureter management approaches were divided into 3 categories: (1) extravesical tenting for ureteric excision without cystotomy (EXTRAVESICAL); (2) open cystotomy with intravesical bladder cuff excision (INTRAVESICAL); and (3) extravesical excision with endoscopic management of ureteric orifice (ENDOSCOPIC). Data available for each patient included demographic details, distal ureter management approach, pathology and operative details, as well as the presence and location of local or distant recurrence. Clinical outcomes included overall recurrence-free survival and intravesical recurrence-free survival. Survival analysis was performed with the Kaplan-Meier method. Multivariable Cox regression analysis was also performed.Results: A total of 820 patients underwent radical nephroureterectomy with a specified distal ureter management approach at 10 Canadian academic institutions. The mean patient age was 69.6 years and the median follow-up was 24.6 months. Of the 820 patients, 406 (49.5%) underwent INTRAVESICAL, 316 (38.5%) underwent EXTRAVESICAL, and 98 (11.9%) underwent ENDOSOPIC distal ureter management. Groups differed significantly in their proportion of females, proportion of laparoscopic cases, presence of carcinoma in situ and pathological tumour stage (p < 0.05). Recurrence-free survival at 5 years was 46.3%, 35.6%, and 30.1% for INTRAVESICAL, EXTRAVESICAL and ENDOSCOPIC, respectively (p < 0.05). Multivariable Cox regression analysis confirmed that INTRAVESICAL resulted in a lower hazard of recurrence compared to EXTRAVESICAL and ENDOSCOPIC. When looking only at intravesical recurrence-free survival (iRFS), a similar trend held up with INTRAVESICAL having the highest iRFS, followed by ENDOSCOPIC and then EXTRAVESICAL management (p < 0.05). At last follow-up, 406 (49.5%) patients were alive and free of disease.Conclusion: Open intravesical excision of the distal ureter (INTRAVESICAL) during radical nephroureterectomy was associated with improved overall and intravesical recurrence-free survival compared with extravesical and endoscopic approaches. These findings suggest that INTRAVESICAL should be considered the gold standard oncologic approach to distal ureter management during radical nephroureterectomy. Limitations of this study include its retrospective design, heterogeneous cohort, and limited follow-up.