Relationship Between Availability of Urologists and Primary Care Providers and Stage of Diagnosis for Invasive Urinary Bladder Cancer.

INTRODUCTION: With no recommended screening approach, urinary bladder cancer patients rely on referral to urologists to ensure timely diagnosis of bladder cancer. This requires coordination between primary and specialty care. We provide estimates of the relative association between primary care physician and urologist density on stage of urinary bladder cancer diagnosis. METHODS: We used 2010 to 2016 Pennsylvania Cancer Registry data to identify all adult patients diagnosed with bladder cancer. Our primary outcome was locoregional stage of diagnosis, since treatment modality changes and prognosis worsens beyond this stage. Based on patient's residential location at the time of diagnosis we defined both density of urologists and number of primary care providers (defined as providers per population) within the patient's county. We used univariate and multivariate logistic regression to estimate the association between provider density and likelihood of locoregional stage of diagnosis. We also controlled for age, sex, race/ethnicity, insurance type, and year. RESULTS: Our sample included 11,771 urinary bladder cancer patients with 10,607 diagnosed at locoregional stage and 1164 at distant stage. Multivariate regression results show primary care density was associated with significantly higher odds of locoregional stage of diagnosis (odds ratio of 1.05 [95% CI: 1.02-1.08]) while urologist density was associated with significantly lower odds of locoregional stage (odds ratio of 0.65 [95% CI: 0.48-0.89]). CONCLUSIONS: We found primary care density but not urologist density was associated with earlier stage of diagnosis, highlighting the importance of access to primary care and need for timely referral to urologic care.

Concurrent durvalumab and radiation therapy (DUART) followed by adjuvant durvalumab in patients with localized urothelial cancer of bladder: results from phase II study, BTCRC-GU15-023.

BACKGROUND: Patients with bladder cancer (BC) who are cisplatin ineligible or have unresectable disease have limited treatment options. Previously, we showed targeting programmed death-ligand 1 (PD-L1) with durvalumab (durva) and radiation therapy (RT) combination was safe in BC. We now report results from a phase II study evaluating the toxicity and efficacy of durva and RT in localized BC. METHODS: This is a single-arm, multi-institutional phase II study; N=26. Enrolled patients had pure or mixed urothelial BC (T2-4 N0-2 M0) with unresectable tumors and were unfit for surgery or cisplatin ineligible. Patients received durva concurrently with RT ×7 weeks, followed by adjuvant durva × 1 year. PRIMARY ENDPOINTS: (A) progression-free survival (PFS) at 1 year and (B) disease control rate (DCR) post adjuvant durva. Key secondary endpoints: (A) complete response (CR) post durvaRT (8 weeks), (B) overall survival (OS), (C) PFS and (D) toxicity. Correlative studies included evaluation of baseline tumor and blood (baseline, post durvaRT) for biomarkers. RESULTS: Median follow-up was 27 months. Evaluable patients: 24/26 post durvaRT, 22/26 for DCR post adjuvant durva, all patients for PFS and OS. Post adjuvant durva, DCR was seen in 72.7%, CR of 54.5%. 1-year PFS was 71.5%, median PFS was 21.8 months. 1-year OS was 83.8%, median OS was 30.8 months. CR at 8 weeks post durvaRT was 62.5%. Node positive (N+) patients had similar median PFS and OS. DurvaRT was well tolerated. Grade ≥3 treatment-related adverse events: anemia, high lipase/amylase, immune-nephritis, transaminitis, dyspnea (grade 4-COPD/immune), fatigue, rash, diarrhea and scleritis. No difference in outcome was observed with PD-L1 status of baseline tumor. Patients with CR/PR or SD had an increase in naïve CD4 T cells, a decrease in PD-1+CD4 T cells at baseline and an increase in cytokine-producing CD8 T cells, including interferon gamma (IFNγ) producing cells, in the peripheral blood. CONCLUSION: Durva with RT followed by adjuvant durva was safe with promising efficacy in localized BC patients with comorbidities, including N+ patients. Larger randomized studies, like S1806 and EA8185, are needed to evaluate the efficacy of combining immunotherapy and RT in BC. TRIAL REGISTRATION NUMBER: NCT02891161.

FOXA1 repression drives lineage plasticity and immune heterogeneity in bladder cancers with squamous differentiation.

Cancers arising from the bladder urothelium often exhibit lineage plasticity with regions of urothelial carcinoma adjacent to or admixed with regions of divergent histomorphology, most commonly squamous differentiation. To define the biologic basis for and clinical significance of this morphologic heterogeneity, here we perform integrated genomic analyses of mixed histology bladder cancers with separable regions of urothelial and squamous differentiation. We find that squamous differentiation is a marker of intratumoral genomic and immunologic heterogeneity in patients with bladder cancer and a biomarker of intrinsic immunotherapy resistance. Phylogenetic analysis confirms that in all cases the urothelial and squamous regions are derived from a common shared precursor. Despite the presence of marked genomic heterogeneity between co-existent urothelial and squamous differentiated regions, no recurrent genomic alteration exclusive to the urothelial or squamous morphologies is identified. Rather, lineage plasticity in bladder cancers with squamous differentiation is associated with loss of expression of FOXA1, GATA3, and PPARG, transcription factors critical for maintenance of urothelial cell identity. Of clinical significance, lineage plasticity and PD-L1 expression is coordinately dysregulated via FOXA1, with patients exhibiting morphologic heterogeneity pre-treatment significantly less likely to respond to immune checkpoint inhibitors.

Impact of an inpatient advanced practice provider on hospital length of stay after major urologic oncology procedures.

INTRODUCTION: Although timely hospital discharge is a complex and multifactorial process, this metric is consistently a focus for hospitals and health care systems. It also has been a long practice that the American Urological Association (AUA) supports the use of advanced practice providers (APPs) as an integral member of the urological care team. MATERIALS AND METHODS: Here, we performed a preliminary evaluation of the effectiveness of an inpatient APP in reducing hospital length of stay (LOS) following major urologic oncology procedures. Surgical outcomes, surgeon data, and LOS for open and minimally invasive urologic oncology procedures, including radical prostatectomy, partial or radical nephrectomy, and radical cystectomy, were compiled over a 4-year period (pre-APP: 2014-2016 and post-APP: 2018-2020). Univariate descriptive statistics analyzed the association of an inpatient APP in with reducing hospital LOS over time. RESULTS: Average LOS decreased in all surgical procedures and for all surgeons in the post-APP setting, irrespective of surgical approach (P< 0.05). CONCLUSIONS: An inpatient APP was associated with a decrease of hospital LOS for urologic oncology patients over time. Such observations underscore the likely economic benefit to the health care system and potential improved coordination of care and satisfaction for patients undergoing major urologic oncology procedures.

Patient Perceptions Regarding Routine Oncologic Follow-Up for Urologic Malignancies.

INTRODUCTION: In colorectal, cervical, and breast cancers, oncologic follow-up can exacerbate or alleviate patient stress about disease recurrence. Such patient experiences are less well defined for urologic malignancies. We developed a cross-sectional prospective survey study to assess kidney (Kid), prostate (Pros), and bladder (Bld) cancer patient perceptions of oncologic follow-up following surgical treatment. PATIENTS AND METHODS: Patients with pTanyNanyM0 Kid, Pros, and Bld cancer presenting at least 60 days following primary surgical treatment of their cancer were eligible. Receipt of adjuvant therapy or disease recurrence were exclusion criteria. Questionnaires assessing attitudes towards follow-up and stress-reducing strategies were administered prior to revealing testing results. Analysis was performed according to cancer type and level of recurrence risk, with pathologic stage used a proxy for recurrence risk. RESULTS: Three hundred thirty-seven patients were prospectively surveyed from 2018 to 2020: 127 (38%) Kid, 134 (40%) Pros, and 76 (23%) Bld. Patients showed satisfaction with provided strategies to combat recurrence anxiety (Kid 86%, Pros 81%, Bld 85%). However, approximately 16% of patients reported wanting, but not receiving, strategies for fear reduction. Most patients reported diagnostic tests were "Not at All" burdensome (Kid 86%, Pros 94%, Bld 82%) and disagree that fewer tests would alleviate anxiety (Kid 89%, Pros 91%, Bld 84%). The majority reported an increased sense of worry if there were no cancer follow-ups (Kid 84%, Pros 80%, Kid 81%), and preferred their specialist to their family physician to direct such care (Kid 89%, Pros 91%, Bld 95%). When stratified by recurrence risk, no significant differences existed across cancers in patients' attitudes toward follow-up. However, Pros cancer patients showed a difference in fear of recurrence ("Not at All" worried about recurrence ≤T2 38%, ≥T3, 19%; P= .04). CONCLUSION: Urology patients appear satisfied with their oncologic follow-up. Sixteen percent of patients sought additional strategies to combat fear, indicating opportunity for improvement.

Diagnostic Imaging in Low-Risk Prostate Cancer: More Harm Than Good?

INTRODUCTION: Despite guidelines recommending that staging imaging is not needed in very low-risk (VLR) and low-risk (LR) prostate cancer (PCa), there is concern for overutilization in these risk groups. We investigate utilization of staging imaging and implications of findings in newly diagnosed VLR and LR PCa patients. METHODS: A total of 493 patients diagnosed with PCa between 2011 and 2017 were stratified according to American Urological Association and National Comprehensive Cancer Network® VLR and LR groups. Computerized tomography (CT), magnetic resonance imaging and bone scan performed at diagnosis was captured and guidelines compliance was evaluated. The significance of radiologist interpreted imaging findings, by imaging type, were classified as normal, nonurological, nonsignificant urological and PCa significant. RESULTS: Greater than 75% of patients in the VLR and LR groups underwent imaging at time of diagnosis. Bone scan was performed in 30% of patients, none of which noted PCa-significant findings, and the majority were normal. CT was utilized in 38% of patients, with only 3 showing PCa-significant findings. Ten CTs showed nonurological/nonsignificant urological findings causing further evaluation. Magnetic resonance imaging was the most utilized scan in low-risk groups, occurring in 70% of patients. Although the majority were normal, 25 scans showed nonsignificant urological findings while only 7 showed PCa-significant findings. CONCLUSIONS: Among VLR and LR PCa patients, there is high overutilization of imaging with most studies yielding minimal PCa-significant findings and further evaluation for incidental observations. This exploratory analysis gives awareness that staging imaging in VLR and LR PCa patients may do more harm than good.

Is pelvic MRI imaging sufficient cross-sectional imaging for staging intermediate and high-risk prostate cancer?

OBJECTIVES: The American Urological Association's (AUA) and National Comprehensive Cancer Network's (NCCN) provide highly recognized guidelines for staging prostate cancer (CaP). However, both are vague as to specific type of cross-sectional imaging (CT vs. MRI) and extent (abdominal vs. pelvis), thereby raising concern for overlapping imaging. We investigated if current AUA and NCCN CaP staging guidelines can become more specific yet maintain sufficient staging. METHODS: We identified 493 patients diagnosed with CaP between 2011 and 2017 and focused analysis on those with AUA and NCCN Intermediate risk (IR) and High risk (HR) groups. Type of staging imaging was recorded and frequency of overlapping (CT + MRI) and abdominal imaging determined. Significance of radiologist findings, for both overlapping and abdominal imaging, were classified as nonurologic, nonsignificant urologic, and CaP significant. RESULTS: Among IR and HR AUA and NCCN risk groups, 82 (35.7%) and 95 (37.3%) patients, respectively, experienced overlapping imaging, of which only 7 patients in AUA and 9 patients in NCCN risk groups had an abnormal CT with normal MRI. However, only 3 of these CTs had CaP significant findings, of which 2 identified bone metastases, which were subsequently detected on bone scan. In regard to the extent of imaging, a total of 157 (68.2%) AUA and 178 (69.8%) NCCN IR and HR patients received abdominal scans, of which only 46 (20.0%) and 49 (19.2%) were abnormal among AUA and NCCN risk groups, respectively. Among these abnormal abdominal scans, only 10 showed CaP significant findings, of which half were suspected bone metastases, and confirmed on recommended bone scan. CONCLUSIONS: Due to nonspecific staging guidelines in IR and HR CaP regarding type and extent of cross-sectional imaging, patients are frequently receiving imaging of overlapping locations. Based on low occurrences of unique CaP significant findings on CT and abdominal imaging, our exploratory analysis suggests that narrowing cross-sectional imaging recommendations to pelvic MRI may reduce imaging overlap while maintaining sufficient staging.

Topical antiseptic at time of transrectal ultrasound prostate biopsy is associated with fewer severe clinical infections and improves antibiotic stewardship.

BACKGROUND: The 2017 AUA White Paper on prevention of prostate needle biopsy (PNB) complications highlights an algorithm for reducing procedural related infections. The incorporation of topical rectal antiseptic (TRS) at time of transrectal PNB is listed as one such modality. We present data on over 1000 transrectal PNB procedures to determine the impact of TRS on 1) infectious complications and 2) use of augmented procedural antibiotics. METHODS: The records of 1181 transrectal PNB procedures performed over a 10-year period were reviewed. In 2013, TRS with either 10% povidone iodine or 4% chlorhexidine was more regularly incorporated into PNB procedures. Clinical and procedural factors were analyzed for association with post-procedure infections. Infectious complications outcomes were compared in patients receiving TRS (n = 566) versus those who had not (n = 615). RESULTS: A total of 990 men underwent 1181 transrectal PNB procedures. Median age of the cohort was 63 years with a median PSA of 7 ng/dL. Of them, 86% of the men were Caucasian, 28% had undergone at least one prior biopsy, 14% were diabetic, and 6% had prior hospitalization within 6 months of the procedure. Five hundred sixty-six patients (48%) received TRS at time of biopsy. Perioperative IV adjunctive antibiotics were used less frequently in patients receiving TRS (13.4% vs. 28.6%, p < 0.001). Furthermore, patients receiving TRS experienced lower rates of clinical infections (1.2% vs. 2.4%, p = 0.14), as well as lower likelihood of severe infections evidenced by decreased rates of hospital admission (0.5% vs. 2.3%, p = 0.013). Rectal vault bacteriology obtained before and after TRS was available in 180 men noting a 98.1% decrease in colony counts after local treatment. CONCLUSIONS: TRS at time of transrectal PNB was associated with decreased use of IV procedural antibiotics as well as decreased severity of infections post-biopsy. This simple technique enhances antibiotic stewardship while simultaneously improving quality outcomes of the procedure.

Can preoperative imaging characteristics predict pT3 bladder cancer following cystectomy?

PURPOSE: Imaging characteristics in bladder cancer (BC), such as hydronephrosis, are predictive of ≥ pT3 disease at time of radical cystectomy (RC). The predictive capacity of other findings, such as perivesical stranding (PS), remains unclear. We investigated whether PS was associated with ≥ pT3 BC in patients who did not receive neoadjuvant chemotherapy (NAC). METHODS: We identified 433 patients with BC who underwent RC from 2003 to 2018 of which 128 did not receive NAC. Evidence of PS on pre-TURBT imaging was determined by radiologist review and a stranding grading system was created. Factors associated with PS and hydronephrosis were identified. Multivariable logistic regressions evaluated PS and hydronephrosis as predictors for ≥ pT3 BC. RESULTS: Of the 128 patients who did not receive NAC, 48 (38%) had pT3 and 12 (9%) had pT4 BC. 125 (98%) patients had CT and three (2%) had MRI. PS and hydronephrosis on imaging were identified in 19 (15%) and 45 (35%) patients. PS was not associated with imaging type (p = 0.38), BMI (p = 0.18), or pathologic T stage (p = 0.24). Hydronephrosis was more frequently associated with higher pathologic T stage (p = 0.034). Multivariable analysis demonstrated that PS was not predictive of ≥ pT3 BC (p = 0.457), while hydronephrosis was positively associated (p = 0.003). Stratification by grade of stranding did not improve the predictive capacity of PS (p = 0.667). CONCLUSION: While hydronephrosis is an indicator of higher stage BC, PS failed to be a reliable predictor of ≥ pT3 stage. These observations should give pause in using PS on imaging to guide decisions until further investigations can be explored.

Perioperative chemotherapy in the management of high risk upper tract urothelial cancers.

Radical nephroureterectomy (RNU) remains the gold-standard in the treatment of invasive urothelial cancers of the upper tract (>pT2). However, there are stage-related, postoperative recurrence and cancer-specific death rates that are unacceptably high. Multimodality treatment regimens including neoadjuvant and adjuvant cisplatin-based systemic chemotherapy have been studied. While there is a paucity of Level 1 evidence to support either regimen, both have advantages and disadvantages. The provision of chemotherapy in the neoadjuvant setting is supported by extensive bladder cancer literature, but randomized controlled trials in the upper tract have not been completed. Neoadjuvant chemotherapy also risks overtreatment of patients due to the lack of accurate pre-operative staging modalities. On the other hand, adjuvant chemotherapy is supported by the findings of one prospective randomized trial, and eliminates the need for patient selection based on imperfect pre-operative modalities. However, the rigors of surgery and the renal function loss related to nephrectomy, may preclude the provision of adjuvant chemotherapy in a significant subset of patients. One may conclude that multimodal therapy is desirable for oncologic control, but the best means of providing such therapy requires further study.

Histologic Heterogeneity of Extirpated Renal Cell Carcinoma Specimens: Implications for Renal Mass Biopsy.

Pathologic characteristics of extirpated renal cell carcinoma (RCC) specimens <7 cm were reviewed to get better information on technical nuances of renal mass biopsy (RMB). Specimens were stratified according to tumor stage, nuclear grade, size, histology, presence of lymphovascular invasion (LVI), necrosis, and sarcomatoid features. When considering pT1 (0-7 cm) tumors, pT1b (4-7 cm) RCC masses were more likely to have necrosis (43% vs 16%, P < 0.001), LVI (6% vs 2%, P = 0.024), high-grade nuclear elements (29% vs 17%, P < 0.001), and sarcomatoid features (2% vs 0%, P = 0.006) compared with pT1a (0-4 cm) tumors. Additionally, pT3a tumors were more highly associated with necrosis (P = 0.005), LVI, sarcomatoid features, and high-grade disease (P for all < 0.001) when compared to pT1 masses. For masses <4 cm, pT3a cancers were more likely to demonstrate necrosis (38% vs 16%, P < 0.001), LVI (22% vs 2%, P < 0.001), high-grade nuclear elements (45% vs 17%, P < 0.001), and sarcomatoid features (12% vs 0%, P < 0.001) compared to pT1a tumors. Similarly, for masses 4-7 cm, pathologic T3a tumors were significantly more likely to have sarcomatoid features (12% vs 2%, P = 0.006) and LVI (22% vs 6%, P = 0.003) compared to pT1b tumors. In summary, pT3a tumors and those RCC masses >4 cm exhibit considerable histologic heterogeneity and may harbor elements that are not easily appreciated with limited renal sampling. Therefore, if RMB is considered for renal masses greater than 4 cm or those that abut sinus fat, a multi-quadrant biopsy approach is necessary to ensure adequate sampling and characterization of the mass.

Development and evaluation of a bladder Cancer specific survivorship care plan by patients and clinical care providers: a multi-methods approach.

BACKGROUND, CONTEXT AND PURPOSE: In spite of the mixed evidence for their impact, survivorship Care Plans (SCPs) are recommended to enhance quality of care for cancer survivors. Data on the feasibility of SCPs in bladder cancer (BC) is sparse. Using a mixed-methods approach, this study describes the iterative development, acceptability and feasibility of BC specific SCP (BC-SCP) in clinical settings. METHODS: In Phase I, we developed the BC-SCP. In Phase II, we conducted four focus groups with 19 patients and 15 providers to examine its acceptability and usability challenges. Data analyses using the Atlas.ti program, informed refinement of the BC-SCP. In Phase III, we conducted feasibility testing of the refined BC-SCP with 18 providers from 12 health-centers. An encounter survey was completed after each assessment to examine the feasibility of the BC-SCP. Chi-square and Fisher Exact tests were used for comparative analyses. RESULTS: During phase I, we observed high patient and provider acceptability of the BC-SCP and substantial engagement in improving its content, design, and structure. In Phase II, providers completed 59 BC-SCPs. Mean time for BC-SCP completion was 12.3 min. Providers reported that BC-SCP content was clear, did not hamper clinic flow and was readily completed with easy-to-access information. Comparative analyses to examine differences in SCP completion time by patient clinico-demographic characteristics and provider type revealed no significant differences. CONCLUSIONS: Our BC-SCP has clinical relevance, and can be used in an active practice setting. However, considerable progress will be necessary to achieve implementation of and sharing the BC-SCP with patients and care providers, particularly within the electronic medical record. In summary, BC-SCPs are essential to improve the follow up care of BC survivors. Clinical resources are required to ensure appropriate implementation of BC-SCPs. TRIAL REGISTRATION: Study HUM00056082.

Hemostatic agent use during partial nephrectomy: trends, outcomes, and associated costs.

PURPOSE: To evaluate the ability of hemostatic agents (HA) to limit bleeding complications following partial nephrectomy (PN) and determine HA usage and costs as well as factors associated with post-operative bleeding complications. METHODS: The records of 429 PN performed for kidney cancers were reviewed for clinical, pathologic, and perioperative variables. Surgical approach, HA use, and HA expenditure were determined. Bleeding complications and management to 90 days after PN were annotated. Wilcoxon rank-sum and two-sample t tests identified factors associated with HA use. Univariate and limited multivariate logistic regression determined variables associated with bleeding complications. RESULTS: Use of HA was associated with longer OR duration, longer ischemia time, higher EBL, and method of PN (OPN and LPN > RPN) (all p values < 0.001). On bivariate analysis, while multiple factors were associated with bleeding complications, neither HA use (p = 0.924) nor the number of HA used (two agents vs one p = 0.712; three agents vs. one p = 0.606) were. A multivariable model noted that increasing RENAL score (p = 0.013) and surgical approach (OPN vs. RPN [p = 0.009] and LPN vs. RPN (p = 0.002]) were independently associated with bleeding complications, while HA use was not (p = 0.294). During the 16 years of analysis, a total of $77,687 USD was spent on HA. Average annual HA expenditure was $4855 USD with the peak being in 2010 where expense was $14,086. Mean annual costs for HA use were greater for OPN vs RAPN starting in 2013 (p = 0.02) CONCLUSIONS: The use of HA during PN was not associated with lower rates of bleeding complications. Therefore, judicious use in a case-specific manner is requisite to limit potentially unnecessary operative cost.

Evaluation of PD-L1 and other immune markers in bladder urothelial carcinoma stratified by histologic variants and molecular subtypes.

Although advanced bladder cancer overall has a poor prognosis, a subset of patients demonstrate durable response to immune checkpoint inhibitors. Evidence shows that the response to checkpoint inhibitors may be associated with type and degree of immune infiltration in the tumor microenvironment. Here, we evaluated immune markers stratified by molecular subtypes and histologic variants. The study utilized a series of urothelial carcinomas (UCs) by tissue microarray, on which histologic variants and molecular subtypes had previously been established. PD1, CD3, CD8 and CD68 expression was evaluated by immunohistochemistry in tumor infiltrating immune cells, while PD-L1 expression in the tumor microenvironment was assessed. Each marker was scored semi-quantitatively (score 0-3). Tumors were clustered by marker scores using agglomerative methods, and associations among markers, histologies, and molecular subtypes were analyzed. PD-L1 expression in the tumor microenvironment significantly correlated with presence of CD3, CD8 and chronic inflammation. Urothelial carcinoma may be classified as either immune high or low based on marker expression. The immune high group is enriched in higher CD3, PD-L1, and genomically-unstable molecular subtype, suggesting it may respond to checkpoint inhibitors. We also identified a degree of intratumoral heterogeneity in immune markers in bladder cancer.

Role of Telemedicine in Urology: Contemporary Practice Patterns and Future Directions.

INTRODUCTION: As outlined in the white paper by the AUA (American Urological Association) Telemedicine Workgroup in 2016, telemedicine has the potential to revolutionize health care delivery and access to urological care. National trends pertaining to the contemporary use of telemedicine in the field of urology have yet to be elucidated. METHODS: A web based survey consisting of 22 questions was developed by the AUA Leadership group in conjunction with the AUA Telemedicine Workgroup, and this questionnaire was sent electronically to 2,324 current AUA members. The questions focused on patterns in telemedicine use and barriers to implementation. RESULTS: A total of 243 responses were received and of these 47% reported an association with institutions that promote telemedicine in some aspect of health care delivery. Overall 26% of respondents reported personal involvement with telemedicine applications at some point in their career. However, only 14% claimed to be actively using telemedicine in their current work. The most commonly cited barrier to the implementation of telemedicine was an inability to effectively bill for services (72%). CONCLUSIONS: While telemedicine is a tool that holds great promise, with many respondents reporting infrastructure for telemedicine applications at their institutions, lack of reimbursement was cited as the major barrier to implementation. This issue regarding reimbursement is a central matter that will need to be standardized moving forward in order to promote widespread use.

Repression of transcription factor AP-2 alpha by PPARγ reveals a novel transcriptional circuit in basal-squamous bladder cancer.

The discovery of bladder cancer transcriptional subtypes provides an opportunity to identify high risk patients, and tailor disease management. Recent studies suggest tumor heterogeneity contributes to regional differences in molecular subtype within the tumor, as well as during progression and following treatment. Nonetheless, the transcriptional drivers of the aggressive basal-squamous subtype remain unidentified. As PPARÉ£ has been repeatedly implicated in the luminal subtype of bladder cancer, we hypothesized inactivation of this transcriptional master regulator during progression results in increased expression of basal-squamous specific transcription factors (TFs) which act to drive aggressive behavior. We initiated a pharmacologic and RNA-seq-based screen to identify PPARÉ£-repressed, basal-squamous specific TFs. Hierarchical clustering of RNA-seq data following treatment of three human bladder cancer cells with a PPARÉ£ agonist identified a number of TFs regulated by PPARÉ£ activation, several of which are implicated in urothelial and squamous differentiation. One PPARÉ£-repressed TF implicated in squamous differentiation identified is Transcription Factor Activating Protein 2 alpha (TFAP2A). We show TFAP2A and its paralog TFAP2C are overexpressed in basal-squamous bladder cancer and in squamous areas of cystectomy samples, and that overexpression is associated with increased lymph node metastasis and distant recurrence, respectively. Biochemical analysis confirmed the ability of PPARÉ£ activation to repress TFAP2A, while PPARÉ£ antagonist and PPARÉ£ siRNA knockdown studies indicate the requirement of a functional receptor. In vivo tissue recombination studies show TFAP2A and TFAP2C promote tumor growth in line with the aggressive nature of basal-squamous bladder cancer. Our findings suggest PPARÉ£ inactivation, as well as TFAP2A and TFAP2C overexpression cooperate with other TFs to promote the basal-squamous transition during tumor progression.

Single-dose radiotherapy disables tumor cell homologous recombination via ischemia/reperfusion injury.

Tumor cure with conventional fractionated radiotherapy is 65%, dependent on tumor cell-autonomous gradual buildup of DNA double-strand break (DSB) misrepair. Here we report that single-dose radiotherapy (SDRT), a disruptive technique that ablates more than 90% of human cancers, operates a distinct dual-target mechanism, linking acid sphingomyelinase-mediated (ASMase-mediated) microvascular perfusion defects to DNA unrepair in tumor cells to confer tumor cell lethality. ASMase-mediated microcirculatory vasoconstriction after SDRT conferred an ischemic stress response within parenchymal tumor cells, with ROS triggering the evolutionarily conserved SUMO stress response, specifically depleting chromatin-associated free SUMO3. Whereas SUMO3, but not SUMO2, was indispensable for homology-directed repair (HDR) of DSBs, HDR loss of function after SDRT yielded DSB unrepair, chromosomal aberrations, and tumor clonogen demise. Vasoconstriction blockade with the endothelin-1 inhibitor BQ-123, or ROS scavenging after SDRT using peroxiredoxin-6 overexpression or the SOD mimetic tempol, prevented chromatin SUMO3 depletion, HDR loss of function, and SDRT tumor ablation. We also provide evidence of mouse-to-human translation of this biology in a randomized clinical trial, showing that 24 Gy SDRT, but not 3×9 Gy fractionation, coupled early tumor ischemia/reperfusion to human cancer ablation. The SDRT biology provides opportunities for mechanism-based selective tumor radiosensitization via accessing of SDRT/ASMase signaling, as current studies indicate that this pathway is tractable to pharmacologic intervention.