Page 76 - CUA Absracts 2022_Fulldraft

2022 CUA Abstracts

bladder cancer (BCa), and to test the effects of prebiotics on the systemic MP-7.7
antitumor efficacy of ICB immunotherapy. The impact of routine bladder biopsies after bacillus Calmette-
Methods: C3H syngeneic male mice were injected subcutaneously with Guérin treatment in patients with pure carcinoma in situ of the
MBT-2 mouse bladder tumor cells. Prebiotics and control water were daily bladder
gavaged until the end of the experiment. Following tumor implantation, Kenneth Huang , Lexia Bao , Martin E. Gleave , Alan I. So , Peter C. Black 1
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mice were treated with four injections of anti-PD1 monoclonal antibody 1 Vancouver Prostate Centre, Department of Urologic Sciences, University
or isotype control intraperitoneally. Tumor growth was monitored twice of British Columbia, Vancouver, BC, Canada
a week. Fecal samples were collected at many timepoints during tumor Introduction: Carcinoma in situ (CIS) has a high rate of recurrence despite
growth for the profiling of gut microbiota. Endpoint tumors were dissociated bacillus Calmette-Guérin (BCG) therapy. Cystoscopy and urine cytology
for flow cytometry analysis of tumor-infiltrating lymphocyte composition. are used for surveillance, but their diagnostic value can be limited by
Results: Independently of immunotherapy, two prebiotics induced a sig- BCG-induced changes. We investigated whether routine bladder biopsy
nificant reduction of tumor growth in comparison to the control group, (RB) can increase early detection of CIS persistence and thereby improve
and improved the overall survival of mice. Interestingly, one prebiotic patient outcome.
combined with anti-PD1 immunotherapy also enhanced the systemic Methods: Patients treated for pure CIS from 2011–2021 were reviewed
antitumor effect of ICB. Interactions between prebiotics and gut micro- retrospectively. All patients were treated with transurethral resection of
biota will be identified by 16S rRNA sequencing analysis while underlying bladder tumor (TURBT) followed by BCG induction and maintenance
mechanisms linking prebiotics treatment with tumor reduction will be therapy with standard surveillance. One urologist performed RB in all
deciphered by the flow cytometry analysis. patients at six months, while all other urologists only performed for-
Conclusions: Overall, our findings support that promising prebiotics can cause biopsy (FC) based on cystoscopic and cytologic abnormalities.
induce an antitumor effect at steady state, and in combination with anti- Outcomes were compared between RB and FC groups according to an
PD-1 treatment, in BCa mouse model. These data will have a significant intention-to-treat analysis.
impact to enhance the clinical response to ICB treatment for BCa patients. Results: Forty-seven patients were included, of whom 23 had RB and
24 had FC. Median ages were 69 years and 76 years in the RB and FC
MP-7.6 groups, respectively, and 36 (77%) were male. Median followup was
External validation of the molecular subtype classifier by three years and 3.5 years in the RB and FC groups, respectively. High-
immunohistochemistry for muscle-invasive bladder cancer grade recurrence was observed within six months in five patients (21.7%)
patients within the trimodal therapy cohort in the RB group and two patients (8.3%) in the FC group. There was
Charles Hesswani , Chelsea L. Jackson , Gautier Marcq , Celine Hardy , no significant difference in the rate of high-grade recurrence during the
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Ronald Kool , Jose Joao Mansure , Fadi Brimo , David Berman , Wassim observation period (p=0.197). Progression to muscle-invasive or locally
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Kassouf 1 advanced bladder cancer was observed in one patient (4.3%) in the RB
1 Department of Urology, McGill University, Montreal, QC, Canada; group and five patients (20.8%) in the FC group (p=0.09). Limitations
2 Department of Pathology and Molecular Medicine, Queen’s University, include small sample size, retrospective analysis, and irregular use of
Kingston, ON, Canada; Department of Pathology, McGill University, cytology in the FC group.
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Montreal, QC, Canada Conclusions: In our single-institutional series of patients with pure CIS,
Introduction: Bladder-sparing approaches for muscle-invasive bladder there was a trend towards a higher rate of recurrence within six months
cancer (MIBC), such as trimodal therapy (TMT), are increasingly offered but lower rate of progression within the study period when patients were
to select candidates. Oncological outcomes may be affected by distinct managed with RB at six months compared to FC biopsy. This suggests that
molecular subtypes based on gene expression profiling. Tumors of the early detection of persistent CIS may prevent later progression.
basal subtype were previously shown to carry a poorer overall survival
(OS) compared to tumors of the luminal subtype. MP-7.8
Methods: Tumoral, benign, and transition zone tissue from transurethral Impact of postoperative opioid use on length of hospital stay
resection of bladder tumors of 104 patients were sampled on five tissue following radical cystectomy
microarray blocks. We measured KRT5, GATA3, and P16 biomarkers Sandra Kim , Wyatt MacNevin , Stewart Whalen , Gregory Bailly , David
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expression on tumoral slides. Hierarchical clustering was used to classify Bell , Ashley R. Cox , Jon Duplisea , Joseph Lawen , Ricardo A. Rendon ,
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patients based on the three-antibody IHC algorithm biomarker expression Ross Mason 1
profile. Subtypes were evaluated for association with complete response 1 Department of Urology, Dalhousie University, Halifax, NS, Canada;
(CR), recurrence-free survival (RFS), and OS. 2 Department of Medicine, Dalhousie University, Halifax, NS, Canada
Results: The median age was 75.0 years (interquartile range 65–80) and Introduction: Radical cystectomy (RC) is associated with high rates of
22.6% were females. Median OS was 43 months (95% confidence interval ileus and bowel complications. There has been increased use of u-opioid
[CI] 19–77) and median followup was 55 months (95% CI 39–75). On receptor antagonists to help combat decreased gastric motility associ-
univariate analysis, Eastern Cooperative Oncology Group (ECOG), and ated with opioid use. However, the relationship between postoperative
CR rate were predictors of significant difference in RFS (p<0.05). For OS, opioid use and length of stay (LOS) is uncertain. This study was aimed
age, ECOG, clinical stage, and CR were found to significantly impact OS at elucidating the relationship between opioid use in postoperative RC
(p<0.05). Of 104 patients, IHC-based subtype classification was feasible patients and LOS.
in 93. Patients were successfully classified into basal (23.7%), luminal Methods: We retrospectively identified any patients who underwent RC
genomically unstable (14.0%), luminal urothelial like (31.2%), and nega- for bladder cancer at our institution between January 2009 and December
tive/unclassified (31.2%). On survival analysis, no significant differences 2019. There were no other inclusion or exclusion criteria. Univariable and
were observed between the molecular subtypes when comparing basal multivariable analyses were used to determine the relationship between
vs. luminal vs. negatives or basal vs. luminal (p>0.05). However, on Cox patient-specific factors associated with increased LOS.
regression analysis at 10 months, the basal subtype showed a poorer Results: A total of 240 patients were included in the study; 81.3% of our
survival compared to the other subtypes combined (hazard ratio [HR] population was male (195/240) with a median age of 70.0 years and
0.376, 95% CI 0.161–0.882, p=0.0245). median body mass index of 27.3. Most patients had T2 disease (54.4%,
Conclusions: Although the classifier was not predictive of CR or survival 124/228), 37.5% (90/240) patients received neoadjuvant chemother-
for MIBC patients post-TMT, tumors of the basal subtype may carry a apy, and ileal conduits were created in 85.4% (205/240) of patients.
poorer prognosis early after treatment. Subtype identification using the The median LOS was 10.0 days and the median daily morphine equiva-
IHC-based three-antibody classification is feasible in most patients. lents (MEqs) were 43.13. Nasogastric (NG) was required in 89 patients
(37.1%), and TPN was given in 56 patients (23.3%) (Table 1). Univariable
linear regression demonstrated that intraoperative transfusion, prior pel-
S74 CUAJ • June 2022 • Volume 16, Issue 6(Suppl1)