Citations

Abstract The outcome of patients with Muscle Invasive Bladder Cancer (MIBC) is highly variable with many patients experiencing progressive disease despite multimodal therapy. A key variable that contributes to poor patient outcomes lies in our inability to predict therapeutic response due to the molecular heterogeneity of MIBC tumors. There is, therefore, a significant unmet clinical need to accurately predict effective drug combinations and therapeutic doses in individual patients with MIBC. Patient-derived tumor organoids (PDOs) have the potential to serve as an ex vivo model of urothelial carcinoma (UC) capable of functionally predicting patient-specific treatment responses. However, current culture procedures typically rely on the expansion of UC organoids from resected tumors or biopsy specimens, which is inherently invasive and hence limits clinical application. We hypothesized that culture of MIBC PDOs can be achieved from urine samples, as is the case in dogs with MIBC, since histopathological features, tumor heterogeneity and subtypes, metastatic activity, and gene expression profiles of canine MIBC mimic those of human MIBC. Herein, we successfully cultured MIBC organoids from both human and canine patients using first-catch urine. Briefly, after centrifuging urine samples to pellet cells, the cells were washed with basal culture media containing FBS and Pen/Strep before being cultured in canine or human culture media containing essential growth factors based on their species of origin. Paraffin-embedded samples were used for molecular characterization by RNA in situ hybridization or immunohistochemistry. Organoids from canine MIBC patients were analyzed for expression of the urothelial differentiation marker (FOXA1) associated with high grade bladder cancer, CD44, a non-kinase transmembrane glycoprotein expressed in UC cancer stem cells, and CK7, an epithelial cell marker that is upregulated in neoplastic UC cells. FOXA1 expression was undetectable in canine MIBC, although CD44 expression was enhanced compared to healthy dog bladder organoids. All canine MIBC organoids had significantly enhanced CK7 expression. Similarly, in human-derived UC organoids, GATA binding protein 3 (GATA3), transcription factor paired box 8 (Pax8), and tumor protein p63 were utilized as markers, with a Pax8-/p63+/GATA3+ profile indicating UC origin of the organoids. Functional response to chemotherapy (cisplatin and gemcitabine) was further assessed using cell viability assay in canine and human UC organoids. Our data suggest that organoids cultured from the urine of patients with MIBC can recapitulate organ structures and maintain marker expression profiles of the original tumor tissues. 3D organoids may provide novel insights to predict therapeutic response to chemotherapy and serve as early diagnostic biomarkers of bladder cancer in both canine and human patients. Citation Format: Dipak Kumar Sahoo, Allison P. Mosichuk, Fabrice Lucien, Igor Frank, John C. Cheville, Karin Allenspach, Jonathan P. Mochel. Urine-derived urinary carcinoma organoids: A novel tool for providing new insights into human and canine bladder cancer treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3092.

Context.— In women, radical cystectomy includes removal of the bladder, uterus, fallopian tubes, ovaries, and anterior vaginal wall, yet contiguous extension of urothelial carcinoma to all pelvic organs is rare and routine removal may be unnecessary. Objective.— To study pelvic organ involvement in women at radical cystectomy and investigate oncologic outcomes. Design.— Women with bladder cancer who underwent radical cystectomy at the Mayo Clinic and University of Toronto (1980–2018) were evaluated. Cancer-specific survival (CSS) was estimated with the Kaplan-Meier method; comparisons were made with the log-rank test. Associations with CSS were evaluated with Cox proportional hazard modeling. Results.— A total of 70 women with pT4a and 83 with pT3b cancer were studied. Organs involved were vagina (n = 41 of 70; 58.6%), uterus (n = 26 of 54; 48.1%), cervix (n = 15 of 54; 27.8%), fallopian tubes (n = 10 of 58; 17.2%), and ovaries (n = 7 of 58; 12.1%); 22 of 58 patients (37.9%) had >1 organ involved. Of 70 with pT4a cancer, 64 were available for survival analysis by 3 pelvic organ groups: vaginal only, vaginal and/or cervical/uterine, and vaginal and/or cervical/uterine and/or fallopian tubes/ovarian involvement. Three-year CSS for vaginal involvement only was 39%; it was 14% if cervical/uterine involvement, and <1% if fallopian tube/ovarian involvement was included (P = .02). Among 20 women with pT4aN0/Nx and vaginal involvement only, 3-year CSS for vaginal involvement was 50%, whereas among 48 women with pT3bN0/Nx cancer, 3-year CSS was 58%, P = .70. Conclusions.— Isolated vaginal involvement should be separated from uterine and/or adnexal extension of urothelial carcinoma at pathologic staging. Direct ovarian extension is rare and routine removal may be unnecessary.

Objectives. To compare the clinicopathologic characteristics of urothelial carcinoma (UC), urothelial carcinoma with squamous differentiation (UCSD), and squamous cell carcinoma (SCC) of the bladder, which have been suggested to differ in terms of risk factors, immunophenotype, and prognosis. Methods. We evaluated the clinicopathologic features of radical cystectomy specimens between 1980 and 2015 with a diagnosis of SCC, UCSD, and UC. PD-L1 immunohistochemistry (clinically available clones 22C3, SP142, and SP263) was performed on SCC and UCSD. Multivariate Cox regression was used to identify prognostic factors. Kaplan–Meier curves were plotted to assess cancer-specific survival (CSS). Results. Of the 1478 cases, there were 1126 UC (76%), 217 UCSD (15%), and 135 SCC (9%). Bladder cancer was more common in men than women (80% vs 20%, P < .0001). However, a higher proportion of SCC and UCSD occurred in women (SCC-36%, UCSD-22%, UC-18%). Women were significantly more likely to be never smokers in all 3 cohorts (UC: 45% vs 16%, UCSD: 44% vs 12%, SCC: 40% vs 18%, P < .0001). Patients with SCC and UCSD were at a higher pathologic stage (>pT2) at the time of cystectomy (UCSD-74%, SCC 71%, UC-44%, P < .0001) and had worse CSS compared to patients with UC ( P = 0.006). SCC had higher PD-L1 scores (all clones) than UCSD ( P < .0001). PD-L1 22C3 ( P = .02, HR: 0.36) and SP142 scores ( P = .046, HR: 0.27) predicted CSS on Kaplan–Meier analysis for SCC cases. Conclusions. UC, UCSD, and SCC are associated with different risk factors, gender distributions, and clinical outcomes. PD-L1 is expressed in SCC and UCSD, suggesting some patients may benefit from targeted therapy.

421 Background: Reported rates of adherence to post-radical cystectomy (RC) surveillance guidelines in real-world practice have been as low as 9%, in part reflecting a nihilistic view held by many of the value of routine follow-up. Indeed, conflicting data exist regarding the outcomes of patients with cancer recurrence detected by scheduled surveillance versus symptom-directed evaluation. Herein, we assessed comparative outcomes of patients with symptomatic recurrence (SR) versus asymptomatic recurrence (AR) after RC. Methods: We reviewed our Institutional Registry of RC patients to identify patients with cancer recurrence following RC. Presenting symptoms in the SR cohort included pain, constitutional symptoms, gastrointestinal symptoms, and hematuria/voiding symptoms, whereas AR was defined as recurrence detected on routine surveillance in the absence of symptoms. Baseline demographic and clinical characteristics were compared between study groups using chi-square and t-test. Kaplan-Meier and Cox survival analyses were performed to compare cancer-specific survival (CSS) and overall survival (OS) between AR and SR groups. Results: Of 3822 patients who underwent RC from 1980-2018 (with a median follow-up after RC of 2.4 years (IQR 1.1,5.5), a total of 1100 were subsequently diagnosed with recurrence, including 311 (28.3%) with AR and 789 (71.7%) with SR. Median time from RC to recurrence was longer in the AR group (13.2 months) than in the SR group (10.8 months; p = 0.01). Presenting symptoms included pain (70.2%), constitutional symptoms (50.7%), gastrointestinal symptoms (23.3%), and urinary symptoms (23.3%). Median follow-up after recurrence was 2.4 years (IQR 1.1-5.5), during which time 997 patients died, including 840 who died of bladder cancer. Compared to patients with SR, patients with AR had a longer median CSS (54.5 months vs 27.3 months, p < 0.001) and OS (43.0 months vs 25.8 months, p < 0.001). On multivariable Cox proportional hazards models adjusting for demographic and clinical factors, SR was associated with a significantly increased risk of cancer-specific (hazard ratio [HR] 1.66 [95% confidence interval 1.41-1.96], p < 0.0001) and all-cause mortality (HR 1.48 [1.23-1.71], p < 0.0001). Conclusions: SR after RC is associated with worse oncologic outcomes than post-RC recurrence detected by routine surveillance. As such, continued surveillance is warranted, while further study is needed to determine the optimal follow-up regimen balancing patient and disease risks.