Complications of single-port robot-assisted radical prostatectomy: multi-institutional analysis from the Single-Port Advanced Research Consortium (SPARC)

OBJECTIVE

To evaluate the perioperative complications of single-port robot-assisted radical prostatectomy (SP-RARP).

PATIENTS AND METHODS

A retrospective review was performed on the prospectively maintained, Institutional Review Board-approved, multi-institutional Single-Port Advanced Research Consortium (SPARC) database. A total of 1103 patients were identified who underwent three different approaches of SP-RARP between 2019 and 2022 using the purpose-built SP robotic platform. In addition to baseline clinical, perioperative outcomes, this study comprehensively analysed for any evidence of intraoperative complication, as well as postoperative complication and readmission within 90 days of the respective surgery.

RESULTS

Of the 244, 712, and 147 patients who underwent transperitoneal, extraperitoneal, and transvesical SP-RARP, respectively, intraoperative complications were noted in five patients (0.4%), all of which occurred during the transperitoneal approach. Two patients had bowel serosal tears, two had posterior button-holing of the bladder necessitating repair, and one patient had an obturator nerve injury. Postoperative complications were noted in 143 patients (13%) with major complications (Clavien-Dindo Grade ≥III) only identified in 3.7% of the total cohort. The most common complications were lymphocele (3.9%), acute urinary retention (2%), and urinary tract infection (1.9%). The 90-day re-admission rate was 3.9%.

CONCLUSION

The SP-RARP is a safe and effective procedure with low complication and readmission rates regardless of the approach. These results are comparable to current multi-port RARP literature.

Low Risk of Postoperative Hernia Following Single-port Robot-assisted Radical Prostatectomy: A Report From the Single-port Advanced Research Consortium (SPARC)

OBJECTIVE

To evaluate the risk of postoperative hernia following different approaches of single-port robot-assisted radical prostatectomy (SP-RARP).

METHODS

A retrospective review was performed on patients who underwent SP-RARP between February 2019 and December 2022. Demographic and clinical information was collected from the multi-institutional, prospectively-maintained Single-Port Advanced Research Consortium (SPARC) database. Data were analyzed using IBM Statistical Packaging for Social Sciences (SPSS) version 29.0 with descriptive statistics as presented.

RESULTS

A total of 1103 patients were identified, consisting of 244 (22.1%), 712 (64.6%), and 147 (13.3%) cases performed via transperitoneal, extraperitoneal (EP), and transvesical (TV) approaches, respectively. During a median follow-up time of 11 months (interquartile range 5.7-17.1 months), only two cases of incisional hernia were reported. Both cases occurred following transperitoneal SP-RARP with one patient requiring surgical repair. There remains no evidence of postoperative hernia following EP and TV SP-RARP at the completion of our review.

CONCLUSION

SP-RARP was associated with low risk for postoperative hernia. The risk was lower following TV and EP SP-RARP where the peritoneum is preserved.

Single-port Extraperitoneal and Transperitoneal Radical Prostatectomy: A Multi-Institutional Propensity-Score Matched Study

OBJECTIVE

To compare the perioperative and early postoperative outcomes between single-port (SP) extraperitoneal radical prostatectomy (EPRP) and SP transperitoneal radical prostatectomy (TPRP), in a multi-institutional setting.

METHODS

We identified all patients who underwent SP robot-assisted radical prostatectomy at 6 different institutes. Data of 650 patients were collected and divided into 2 groups based on the surgical approach: SP EPRP or SP TPRP. A Propensity-score matched-pair analysis for body mass index (BMI), prostate size, and National Comprehensive Cancer Network risk was performed with a 1:1 ratio. Analysis of perioperative and postoperative outcomes was performed using Wilcoxon signed-rank test and chi-square and Fisher's exact tests.

RESULTS

After matching, 238 patients were included in each arm. The median follow-up period was 7 and 6 months for EPRP and TPRP groups, respectively. The total operative time was longer in the EPRP group (206 vs 155 minutes, P < .001). The EPRP group had a shorter length of hospitalization and same-day discharge rate compared to the TPRP approach (P < .001). There was no difference in the overall intraoperative or postoperative complications rate between the 2 groups, nor positive surgical margin rates.

CONCLUSION

The SP extraperitoneal approach is associated with a shorter hospital stay and higher rate of same-day discharge, with no difference in the surgical margin, or complication rates.

Renal Hilar Clamping With a Standard Robotic Bulldog Clamp Using the Single Port da Vinci Robot

BACKGROUND

Renal hilar clamping during a robotic partial nephrectomy is essential for a successful, nephron-sparing tumor resection. Standard robotic bulldog clamps are modified to accommodate multiport robotic surgical systems with alterations including knobs to fit robotic forceps and reduced spring tension. Despite the lower spring tension, a standard robotic bulldog clamp cannot be loaded and opened using one Single Port robotic arm. The angled path instrument cables take through multiple robotic arm articulations lowers the maximum force generated by Single Port instruments to below what is necessary to load and open a robotic bulldog clamp.

OBJECTIVE

To share institutional knowledge gained regarding safe and efficient hilar clamp placement and removal using the da Vinci Single Port Surgical System with a standard robotic bulldog clamp. As the da Vinci Single Port system gains wider use, knowledge of this technique will reduce surgeon trial-and-error during first experiences using the Single Port system with bulldog clamps.

MATERIAL

Video obtained during two partial nephrectomies, da Vinci Single Port Surgical System, Scanlan Reliance 25 mm curved robotic bulldog clamp, Final Cut Pro video editing software.

RESULTS

A controlled sequence of steps for renal hilar clamping and subsequent clamp removal using a standard robotic bulldog clamp with the da Vinci Single Port Surgical System.

CONCLUSION

The demonstrated technique for intracorporeal loading, opening, and placement of a standard robotic bulldog clamp using the da Vinci Single Port Surgical System is feasible and efficient.

Validation of MSKCC pre-prostatectomy nomogram in men who undergo MRI-targeted prostate biopsy prior to radical prostatectomy

14

Background: The Memorial Sloan Kettering Cancer Center (MSKCC) Pre-Prostatectomy nomogram is a widely used resource using clinical factors to predict the likelihood of adverse pathology at radical prostatectomy. The increasing adoption of magnetic resonance imaging (MRI) and MRI-targeted biopsy (TB) permits optimized detection of clinically-significant cancer over systematic biopsy sampling alone. We aim to validate the prognostic utility of the MSKCC Pre-Prostatectomy nomogram with TB pathology results. Methods: Men who underwent systematic extended-sextant prostate biopsy (SB) followed by MRI TB who later underwent radical prostatectomy at our institution were included. Patient information was entered into the MSKCC Pre-Prostatectomy nomogram using five biopsy reporting schemes (SB alone, TB alone reported each of two ways (individual core (IC) technique or aggregate cores (AG) technique combining cores from a single MRI targeted lesion), and SB with TB combined with TB reported by both IC and AG methods. The likelihood of extracapsular extension (EPE), lymph node involvement (LNI), and seminal vesicle invasion (SVI) as predicted by the nomogram for each biopsy reporting schema were compared to radical prostatectomy pathology. Results: We identified 63 men from January 2014 to November 2017. On ROC analysis, IC-TB, AG-TB, SB plus IC-TB, and SB plus AG-TB exhibited similar, if not improved, AUC compared to SB alone in predicting EPE (0.671, 0.674, 0.658, and 0.6613 versus 0.6085). For LNI, superior AUC was observed for AG-TB (0.647) compared to IC-TB (0.571) and SB alone (0.524) Equivocal SVI prediction was observed for SB plus IC-TB compared to SB alone (0.727 versus 0.733). Conclusions: Using TB pathology results either alone or combined with SB pathology results for the MSKCC Pre-Prostatectomy nomogram appears comparable, if not improved, in prognosticating adverse pathologic features on radical prostatectomy compared to using SB core data alone from which the nomogram was developed.

Phase Ib trial of ALT-803, an IL-15 superagonist, plus BCG for the treatment of BCG-naïve patients with non-muscle-invasive bladder cancer

510

Background: The current standard of care for patients with high risk NMIBC is a TURBT or biopsy followed by a 6-week induction course of intravesical BCG and supplementary maintenance therapies every 3 months thereafter (Lamm 2000). While clinical response is significantly improved with BCG, 50% of patients are still expected to recur within 12 months ( Sfakianos 2014). The pursuit of novel agents to prevent progression and recurrence of NMIBC remains critical. This phase Ib clinical trial evaluates the safety and tolerability of ALT-803, an IL-15 superagonist, plus BCG in BCG-naïve NMIBC patients. Methods: A dose escalation 3+3 design was employed to evaluate intravesical ALT-803 plus 50 mg BCG in BCG-naïve patients with intermediate or high-risk Ta, T1 or Tis stage NMIBC. Patients received intravesical ALT-803 in conjunction with BCG weekly for 6 consecutive weeks (induction) and then encouraged (but not required) to receive maintenance BCG alone as per standard practices. Patients had a routine cystoscopy and voided urinary cytology (VUC) every 3 months for 2 years to determine response. Negative cystoscopy, VUC and/or biopsy yielded a complete response (CR). No cohort (100, 200 or 400 μg/instillation ALT-803) experienced any dose limiting toxicities. Results: All patients are disease-free (CR) at 24 months; no patients experienced disease recurrence or progression. Adverse events consistent with SoC BCG treatment (hematuria and urinary tract pain) were reported in all cohorts. One patient experienced a grade 3 adverse event of hypertension that resolved the same day. No grade 4 toxicities or DLTs were observed. Clinical trial information: NCT02138734. Conclusions: Intravesical ALT-803 plus BCG treatment is well tolerated in BCG-naïve patients with NMIBC. All patients are disease-free 24 months after treatment with BCG and ALT-803. A randomized phase II trial is currently underway.[Table: see text]

Prognostic classification of muscle-invasive bladder cancer (MIBC) following radical cystectomy (RC) alone or with perioperative chemotherapy: Analysis of the U.S. National Cancer Database (NCDB)

372

Background: While the role of adjuvant therapy for MIBC is being evaluated in randomized trials of patients (pts) following RC with or without neoadjuvant chemotherapy (NC), pts receiving adjuvant chemotherapy (AC) have been excluded. Understanding the prognosis of a broad spectrum of pts undergoing RC with or without perioperative chemotherapy may aid patient selection, stratification and interpretation of nonrandomized data. We conducted a retrospective analysis of the NCDB to construct a comprehensive prognostic nomogram in this broad population. Methods: Data from NCDB was obtained for all patients diagnosed with clinical (c)-T2-T4aN0M0 urothelial carcinoma of bladder who underwent RC in the US from 2004-2013. Those who underwent RC > 6 months (mo) after initiating NC, received AC > 4 mo after RC were excluded to allow only those receiving optimal therapy. Pts with unknown race and number of lymph nodes (LNs) examined were also excluded. Multivariate analyses were conducted to determine the impact on survival of: clinical stage, pathologic (p)-stage, treatment group (RC alone, NC, AC), age, year of diagnosis, Charlson Comorbidity Index (CCI), race, number of examined LNs examined and sex. Results: A total of 10,256 pts were evaluable for analysis: 6864 in the RC group, 1380 in the AC group and 2012 in the NC group. On multivariate analysis, the following variables were significantly (p < 0.001) associated with survival: treatment group, age ( < 65 vs. ≥ 65 years), CCI, p-stage and number of examined LNs. Calibration was performed and the c-index was 0.79 (95% CI: 0.76-0.81). Limitations of a retrospective analysis apply. Conclusions: A comprehensive prognostic nomogram to predict the survival of pts with MIBC undergoing RC with or without NC or AC was proposed. The estimation of residual risk of mortality after RC alone or with AC or NC aids optimal stratification of pts in more inclusive randomized trials of subsequent adjuvant therapy. The nomogram also highlights the impact of comorbidities and age, and helps interpret non-randomized data evaluating perioperative regimens.

Satisfying the fatty acid demand of prostate cancer: De novo synthesis versus uptake as alternative and potentially cooperative prostate cancer phenotypes

107

Background: Malignant transformation increases cellular demand for fatty acids (FA). Many cancers show increased expression of fatty acid synthase (FASN); FASN catalyzes the de novo synthesis of the FA palmitate. While research has focused on FASN and de novo tumor FA synthesis, observations suggest that alternate mechanisms for FA acquisition are also important, including studies showing that cancer cells can be rescued from FASN inhibition by exogenous palmitate. Using a biopsy-based approach, we identified a PrCa subtype with outlier (>10 fold) overexpression of fatty acid binding protein 5 (FABP5). FABP5 facilitates the utilization of palmitate and other FAs from outside the cell; a FABP5 overexpression phenotype may confer a selective advantage when dietary FAs are abundant or when FASN is targeted as a therapy. Methods: 244 prostate biopsy patients were prospectively enrolled. Tissue prints were collected from each core for RNA and DNA preparation. mRNA was analyzed using Affymetrix arrays and TaqMan qrtPCR assays. Immunohistochemistry (IHC) was performed using archival radical prostatectomy (RP) specimens. Results: mRNA analyses revealed a PrCa subtype with >10 x overexpression of FABP; this phenotype was observed in 7% of 268 cores with Gleason sum (GS) 7-10 PrCa. We also observed a second subtype with >10 x overexpression of FASN in 9% of GS 7-10 cores. With few exceptions these two PrCa subtypes showed an “either-or” pattern with top-quartile overexpression of FABP5 or FASN but not both (Spearman r = - 0.385; P < 0.0001). IHC confirmed variable expression, including “patchwork” PrCas with high Gleason pattern (GP) areas overexpressing FABP5 next to low GP areas overexpressing FASN. The net result may be a selective advantage for the high grade cancer if FABP5 allows it to exploit the FA being synthesized by the adjacent low grade focus Conclusions: Identification of a PrCa subtype with high levels of FABP5 overexpression suggests a previously unrecognized mechanism by which some PrCas can increase FA supply without de novo synthesis; such a PrCa subtype might be particularly sensitive to dietary interventions and relatively insensitive to FASN inhibitors.

Abstract C40: A biopsy-focused approach to molecular studies of prostate cancer in African Americans: the Birmingham Alabama Prostate Cancer Consortium (BAPrCa)

Cancer health disparities can arise from research studies in which the study subjects are not representative of the populations affected by the disease. In prostate cancer (PrCa) biorepositories, most of the frozen samples collected for molecular analyses are obtained from radical prostatectomy (RP) specimens. However, tissue collections based on RP specimens do not include patients who are diagnosed with relatively advanced disease and treated with first-line hormonal and/or radiation therapy rather than surgery; African Americans (AA) are more likely than European Americans (EA) to be diagnosed with this type of advanced prostate cancer. With support from the DOD Prostate Cancer Research Program, our research team has established the Birmingham Alabama Prostate Cancer Consortium (BAPrCa) with a major focus on studies that use prostate biopsies for the molecular analysis of PrCa in AAs. To ensure that there is no compromise of biopsy diagnosis, we use innovative tissue print technologies to obtain snap frozen nitrocellulose blots from each of the prostate biopsy cores. These biopsy tissue prints provide high quality RNA and DNA for molecular and genetic studies. Our biopsy-based analysis of high risk cancers has revealed PrCa subtypes that were either unrecognized or significantly underestimated in previous prostatectomy-based studies.

As of June 2016 more than 250 prostate biopsy patients have been prospectively enrolled in the BAPrCa prostate biopsy tissue print study; just under half (48%) of these study subjects self-identify as AA. Each biopsy from each study subject was tissue printed to generate more than 3000 unique pairs of high quality RNA and DNA samples. AA men were enrolled from two study sites in Birmingham Alabama, an academic medical center (University of Alabama at Birmingham, UAB) and a large urology private practice (Urology Centers of Alabama, UCA). The prevalence of prostate cancer diagnosed in our AA study subjects undergoing standard biopsies was 51%, with 30% showing cancer of Gleason 7 or more. A higher proportion of AA subjects were diagnosed with PrCa at UAB (61% cancer positive; 45% with Gleason 7 or more) compared to UCA (44% cancer positive; 20% with Gleason 7 or more). The difference between AA cancer diagnoses observed between our two study sites may in part result from differences in the criteria for biopsy; pre-biopsy PSA was less than 4 ng/ml for 25% of UCA subjects but for only 2% of UAB subjects.

PSA criteria for prostate biopsy may have a significant and unrecognized impact on the detection of prostate cancer in contemporary AA populations. The BAPrCa study cohort provides a unique opportunity to evaluate the PrCa subtypes diagnosed in AAs using different PSA criteria for biopsy, especially in a deep south AA population.

Citation Format: Sandra M. Gaston, Dennis Otali, James Kearns, Kerry Dehimer, George W. Adams, Soroush Rais-Bahrami, Jeffrey Nix, James E. Bryant, Peter Kolettis, William E. Grizzle. A biopsy-focused approach to molecular studies of prostate cancer in African Americans: the Birmingham Alabama Prostate Cancer Consortium (BAPrCa). [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr C40.

Multi-institutional evaluation of multiparametric MRI and fusion-guided prostate biopsy in a biopsy-naive population

60

Background: Multiparametric MRI (mpMRI) and fusion biopsy (FB) has proven beneficial in men with a prior negative systematic biopsy (SB) or diagnosis of prostate cancer (CaP). The aim of the study was to evaluate mpMRI and FB in a biopsy-naive population. Methods: A multi-institutional review was performed on patients with no prior biopsy history who underwent mpMRI followed by concurrent FB and SB. Imaging protocol was standardized across institutions. Gleason score (GS) distribution/risk classifications were recorded. Univariate analysis was performed to compare FB versus SB. Results: A total of 361 biopsy-naive men were identified from 4 institutions. GS distribution/risk classification for FB and SB are presented in the table. Overall cancer detection rate (CDR) was 65.4%. In biopsy-naive men, FB detected a greater absolute number of high grade disease with 13% more high risk CaP than SB (78 vs 69). Additionally, FB detected 21% fewer cases of GS 6 CaP (57 vs 69). The CDR for FB alone was 57.3% with only 3 intermediate-risk and 1 high-risk patient not identified. The addition of SB to FB resulted in diagnosing 25 added cases of low-risk disease for each high risk CaP detected. The CDR of SB alone was 59.6%, however, 2 intermediate- and 4 high-risk CaP were missed. The addition of FB to SB alone resulted in only 4 added cases of low-risk CaP for each high-risk CaP detected. Conclusions: In biopsy-naive men, mpMRI and fusion biopsy detects a greater number of patients with high-risk disease while decreasing the detection of low-risk CaP. Additional studies with greater power will be required to validate the potential benefit of mpMRI and FB in patients with no prior biopsy history. [Table: see text]

Phase I trial of ALT-801, a first-in-class T-cell receptor (TCR)-interleukin (IL)-2 fusion molecule, plus gemcitabine (G) for Bacillus Calmette Guerin (BCG)-resistant non-muscle-invasive bladder cancer (NMIBC)

451

Background: Novel agents are necessary to treat BCG-resistant NMIBC to avoid radical cystectomy (RC). This phase I clinical trial evaluated the safety and activity of ALT-801, a recombinant humanized TCR-IL-2 fusion protein in BCG-resistant NMIBC. Methods: This is a Phase I trial using the 3+3 design to evaluate intravenous (IV) ALT-801 plus IV G 1000 mg/m2 in BCG-resistant high-risk NMIBC patients (pts) defined as high grade Ta, T1 or carcinoma in situ, size > 4 cm or multi-focal tumors. BCG-intolerant pts, those who refused or were unfit to undergo RC were also eligible. Initially, patients received ALT-801 monotherapy; an amendment added G. Pts received induction of 2 cycles, with a 13-day rest between cycles. Each cycle consisted of 4 doses of ALT-801 on Day 3, Day 5, Day 8, and Day 15 and 2 doses of G, one each on Day 1 and Day 8. Pts who have a biopsy-proven complete response (CR) after induction received one maintenance cycle and underwent response assessment. The initial dose of ALT-801 was 0.08 mg/kg with 2 step-down doses allowed if dose limiting toxicities (DLTs)- 0.06 mg/kg and 0.04 mg/kg. Results: 2 pts in cohort one received ALT-801 alone at 0.08 mg/kg per dose, a 3rd pt received G and ALT-801 at 0.08 mg/kg per dose. Grade ≥ 3 hepatotoxicity in the 3rd patient led to a step-down to 0.06 mg/kg dose. One pt in the 0.06 mg/kg dose experienced a DLT (Grade ≥ 3 hepatotoxicity) and the cohort was expanded to 6 pts with no further DLTs. Other attributed adverse events were: anorexia, pruritus, rash, edema, fatigue, chills. For the 0.06 mg/kg ALT-801 + G regimen, 6 pts received up to 2 cycles of induction and 4 pts received the maintenance cycle. All pts have completed therapy without further DLTs. CR was observed in 3 pts, which was durable in 2 pts lasting ≥ 18 months. Preliminarily immune studies have shown transient IFN-γ and IL-6 but not TNF-α and IL-10 induction after ALT-801 dosing. Conclusions: ALT-801 plus gemcitabine was feasible in BCG-resistant NMIBC and demonstrated immune responses and potential durable clinical activity. Further evaluation in expansion cohorts in a phase Ib/II trial is planned. Clinical trial information: NCT01625260.

Phase Ib trial of ALT-803, an IL-15 superagonist, plus Bacillus Calmette Guerin (BCG) for the treatment of patients with BCG-naïve non-muscle-invasive bladder cancer (NMIBC)

470

Background: Novel agents are necessary to treat NMIBC to avoid recurrence and progression. This phase Ib clinical trial evaluated the safety and toleraibility of ALT-803, an IL-15 superagonist, plus BCG in patients with BCG-naïve NMIBC. Methods: This is a Phase Ib trial using the 3+3 design to evaluate intravesical ALT-803 plus BCG 50 mg in BCG-naïve NMIBC patients, who would normally be eligible for intravesical BCG alone. The initial dose of ALT-803 was 100 μg/instillation with 2 dose-escalations allowed (200 μg/instillation and 400 μg/instillation) if dose limiting toxicities (DLTs) were not evident. Patients received intravesical ALT-803 in conjunction with BCG weekly for 6 consecutive weeks (Induction Phase). Patients then had routine follow-up with cystoscopy and voided urinary cytology (VUC) every 3 months for 2 years equating to confirmatory response assessment. Negative cystoscopy, VUC and/or biopsy yielded a complete response (CR). When appropriate for high-risk patients, physicians and patients were encouraged to receive maintenance BCG alone as per common practice patterns. Results: No patient in 100 μg/instillation of ALT-803/BCG and 200 μg/instillation of ALT-803/BCG reported an AE. One patient in 400 μg/instillation/BCG cohort developed a urinary tract infection requiring delay of intravesical treatment by 1 week. No grade 3/4 toxicities were noted. All patients have completed therapy without DLTs. To date, 4 patients have 12 month follow-up and are CR. The remaining 5 patients have no evidence of disease. However, follow-ups are currently approximately 3 months. Corollary immune studies are still pending. Conclusions: Intravesical ALT-803 plus BCG was safe and tolerable in patients with BCG-naive NMIBC. Further evaluation in expansion cohorts in a phase II trial is currently underway. Clinical trial information: NCT02138734.

Abstract SY29-02: The use of innovative prostate biopsy tissue print techniques for molecular genomic, epigenomic and gene expression studies

Cancer health disparities can arise from research studies that use biospecimens that are not representative of the populations affected by the disease. In biorepositories at research oriented hospitals that support molecular biomarker research, an under-representation of important clinical subpopulations can result from practices that govern conventional biorepository collection of discarded tissues from surgical specimens. In prostate cancer biorepositories, most of the frozen samples are obtained from radical prostatectomy (RP) specimens. However, tissue collections based on RP specimens do not include patients who are diagnosed with relatively advanced disease and treated with first-line hormonal and/or radiation therapy rather than surgery; African Americans are more likely than European Americans to be diagnosed with this type of advanced prostate cancer. Moreover, RP collections have a limited representation of patient groups that preferentially choose non-surgical treatment for organ confined prostate cancer; such a preference for non-surgical treatment has been observed for African American prostate cancer patients in many areas of the US. Our collaborative group utilizes innovative prostate biopsy tissue print techniques to obtain a more complete representation of the men who are being evaluated for prostate cancer, including the patients with a biopsy diagnosis of “no cancer” and prostate cancer patients who chose active surveillance or non-surgical treatment rather than radical prostatectomy. Prostate biopsy tissue prints consist of nitrocellulose blots collected from each of the fresh tissue cores as it is transferred from the biopsy needle. This nitrocellulose blotting step is simple, inexpensive and results in no compromise of the biopsy tissue for surgical pathology. We have used snap-frozen tissue prints as the source of prostate tissues for multiple biomarker studies, including array-based and sequence-based profiling techniques that require high quality DNA and RNA. Because prostate biopsy tissue prints are easily collected in an outpatient office setting, this approach has allowed us to expand the Birmingham Area Prostate Cancer Biorepository (BAPrCAR) to include a multi-center urology practice that serves large numbers of African Americans and performs prostate biopsies on over 2000 patients per year. Prostate biopsy tissue prints have also been important in our studies of molecular marker correlations of magnetic resonance image (MRI) defined criteria of prostate cancer suspicion; our goal is to optimize the use of MRI/ultrasound guided biopsies for both African American and European American patients who are considering active surveillance. We have successfully used prostate biopsy tissue print samples to characterize multiple molecular biomarkers in parallel, including ancestry informative SNPs, mRNA and miRNA transcripts, genomic mutations and DNA methylation-marker patterns. In summary, our experience demonstrates that biopsy tissue print techniques provide an innovative, practical approach to overcoming disparities in prostate cancer research by significantly expanding patient representation in the frozen biorepository collections used for molecular biomarker discovery and translational studies.

Citation Format: Sandra M. Gaston, William E. Grizzle, Rick Kittles, Jihad Hayek, Peter N. Kolettis, Soroush Rais-Bahrami, Jeffrey Nix, Jennifer Gordetsky, George W. Adams, Gary P. Kearney. The use of innovative prostate biopsy tissue print techniques for molecular genomic, epigenomic and gene expression studies. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr SY29-02. doi:10.1158/1538-7445.AM2015-SY29-02

Diagnostic value of biparametric MRI as an adjunct to PSA-based detection of prostate cancer

193

Background: To determine the diagnostic yield of analyzing a fast, cost-conscious biparametric (T2 and diffusion-weighted) MRI (B-MRI) for prostate cancer (PCa) detection as an adjunct to to standard digital rectal exam (DRE) and prostate specific antigen (PSA)-based screening. Methods: Review of patients who were enrolled in a trial to undergo MP-MRI and MR/US fusion-guided prostate biopsy at our institution identified 143 men who underwent MP-MRI in addition to standard DRE and PSA-based PCa screening prior to any other prior prostate biopsy sessions. Patient demographics, DRE staging, PSA, PSA density (PSAD), and B-MRI findings were assessed for association with PCa detection on biopsy. Results: Men with detected PCa tended to be older, with higher PSA, higher PSAD, and increased number of screen positive lesions (#SPL) on B-MRI. B-MRI performed well for the detection of PCa with an area under the curve (AUC) of 0.80 (compared to 0.66 and 0.74 for PSA and PSAD). We derived PSA and MRI-based combined screening formulas for detection of PCa with optimized thresholds. (1) for PSA and B-MRI: PSA + 6 x (#SPL) > 14 and (2) for PSAD and B-MRI: 14 x (PSAD) + (#SPL) > 4.25. Area under the curve for equations 1 and 2 were 0.83 and 0.87 and overall accuracy of PCa detection was 79% in both models. Furthermore, the model integrating PSA with #SPL on B-MRI, was much more efficient at maximally identifying men with Gleason 7 or higher disease compared to PSA-screening alone. Use of model combining PSAD and MRI, the number of bGS 7 or higher cancers that were missed was minimized. Overall, combined use of PSA or PSAD coupled with B-MRI #SPL improved the true positive yield of identifying men with bGS 7 or higher while minimizing the false positive number of men identified as “screen-positive,” but with no cancer on biopsy. Conclusions: Number of positive lesions on B-MRI outperforms PSA alone in detecting PCa, supporting the use of this limited, non-contrast MRI as a potential adjunct tool in PCa screening. Furthermore, this imaging criteria coupled as an adjunct with PSA and PSAD, provides even more accuracy in detecting clinically-significant PCa.

MRI characterization of the dynamic effects of 5α-reductase inhibitors on prostate zonal volumes

INTRODUCTION

Prior studies of volumetric effects of 5α-reductase inhibitors (5ARIs) on the prostate have used transrectal ultrasound which provides poor differentiation of prostatic zones. We utilized high-resolution prostate MRI to evaluate the true dynamic effects of 5ARI in men who underwent multiple MRIs.

MATERIALS AND METHODS

A retrospective study of patients who underwent serial 3.0 Tesla prostate MRI from 2007 to 2012 and were treated with 5ARI were studied. Nineteen patients who had a baseline MRI prior to 5ARI initiation and subsequent MRI follow up were selected. A randomly selected group of 40 patients who had not received any form of therapy was selected as the control cohort. Total prostate volume (TPV), transition zone volume (TZV), and peripheral zone volume (PZV) were calculated using 3D reconstructions and prostate segmentation from T2-weighted MRI. Changes in volumes were correlated with the duration of treatment using linear regression analysis.

RESULTS

Following over 2 years of treatment, 5ARI decreased TPV significantly (16.7%, p < 0.0001). There were similar decreases in TZV (7.5%, p < 0.001) and PZV (27.4%, p = 0.0002) from baseline. In the control group, TPV and TZV increased (p < 0.0001) while PZV remained stable. When adjusted for the natural growth of prostate zonal volume dynamics seen in the control cohort, approximately 60% of the reduction of the TPV from 5ARI resulted from changes in the TZV and 40% of the reduction from changes in the PZV.

CONCLUSIONS

3.0 Tesla MRI characterizations of the dynamic effects of 5ARI on prostate zonal volumes demonstrate significant decreases in TPV, TZV, and PZV. 5ARI blocks the natural growth of TZV as men age and decreases both TZV and PZV below their baselines. As imaging technology improves, prostate MRI allows for more accurate assessment of drug effects on dynamic prostate volumes.

Can magnetic resonance-ultrasound fusion biopsy improve cancer detection in enlarged prostates?

PURPOSE

Patients with an enlarged prostate and suspicion of prostate cancer pose a diagnostic dilemma. The prostate cancer detection rate of systematic 12-core transrectal ultrasound guided biopsy is between 30% and 40%. For prostates greater than 40 cc this decreases to 30% or less. Magnetic resonance-ultrasound fusion biopsy has shown superior prostate cancer detection rates. We defined the detection rate of magnetic resonance-ultrasound fusion biopsy in men with an enlarged prostate gland.

MATERIALS AND METHODS

We retrospectively analyzed the records of patients who underwent multiparametric prostate magnetic resonance imaging followed by magnetic resonance-ultrasound fusion biopsy at our institution. Whole prostate volumes were calculated using magnetic resonance imaging reconstructions. Detection rates were analyzed with respect to age, prostate specific antigen and whole prostate volumes. Multivariable logistic regression was used to assess these parameters as independent predictors of prostate cancer detection.

RESULTS

We analyzed 649 patients with a mean±SD age of 61.8±7.9 years and a median prostate specific antigen of 6.65 ng/ml (IQR 4.35-11.0). Mean whole prostate volume was 58.7±34.3 cc. The overall detection rate of the magnetic resonance-ultrasound fusion platform was 55%. For prostates less than 40 cc the detection rate was 71.1% compared to 57.5%, 46.9%, 46.9% 33.3%, 36.4% and 30.4% for glands 40 to 54.9, 55 to 69.9, 70 to 84.9, 85 to 99.9, 100 to 114.9 and 115 cc or greater, respectively (p<0.0001). Multivariable logistic regression showed a significant inverse association of magnetic resonance imaging volume with prostate cancer detection, controlling for age and prostate specific antigen.

CONCLUSIONS

Transrectal ultrasound guided and fusion biopsy cancer detection rates decreased with increasing prostate volume. However, magnetic resonance-ultrasound fusion biopsy had a higher prostate cancer detection rate compared to that of transrectal ultrasound guided biopsy in the literature. Magnetic resonance-ultrasound fusion biopsy represents a promising solution for patients with suspicion of prostate cancer and an enlarged prostate.

Magnetic resonance imaging/ultrasound-fusion biopsy significantly upgrades prostate cancer versus systematic 12-core transrectal ultrasound biopsy

BACKGROUND

Gleason scores from standard, 12-core prostate biopsies are upgraded historically in 25-33% of patients. Multiparametric prostate magnetic resonance imaging (MP-MRI) with ultrasound (US)-targeted fusion biopsy may better sample the true gland pathology.

OBJECTIVE

The rate of Gleason score upgrading from an MRI/US-fusion-guided prostate-biopsy platform is compared with a standard 12-core biopsy regimen alone.

DESIGN, SETTING, AND PARTICIPANTS

There were 582 subjects enrolled from August 2007 through August 2012 in a prospective trial comparing systematic, extended 12-core transrectal ultrasound biopsies to targeted MRI/US-fusion-guided prostate biopsies performed during the same biopsy session.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The highest Gleason score from each biopsy method was compared.

INTERVENTIONS

An MRI/US-fusion-guided platform with electromagnetic tracking was used for the performance of the fusion-guided biopsies.

RESULTS AND LIMITATIONS

A diagnosis of prostate cancer (PCa) was made in 315 (54%) of the patients. Addition of targeted biopsy led to Gleason upgrading in 81 (32%) cases. Targeted biopsy detected 67% more Gleason ≥4+3 tumors than 12-core biopsy alone and missed 36% of Gleason ≤3+4 tumors, thus mitigating the detection of lower-grade disease. Conversely, 12-core biopsy led to upgrading in 67 (26%) cases over targeted biopsy alone but only detected 8% more Gleason ≥4+3 tumors. On multivariate analysis, MP-MRI suspicion was associated with Gleason score upgrading in the targeted lesions (p<0.001). The main limitation of this study was that definitive pathology from radical prostatectomy was not available.

CONCLUSIONS

MRI/US-fusion-guided biopsy upgrades and detects PCa of higher Gleason score in 32% of patients compared with traditional 12-core biopsy alone. Targeted biopsy technique preferentially detects higher-grade PCa while missing lower-grade tumors.

Magnetic resonance imaging (MRI)-guided transurethral ultrasound therapy of the prostate: a preclinical study with radiological and pathological correlation using customised MRI-based moulds

OBJECTIVE

To characterise the feasibility and safety of a novel transurethral ultrasound (US)-therapy device combined with real-time multi-plane magnetic resonance imaging (MRI)-based temperature monitoring and temperature feedback control, to enable spatiotemporally precise regional ablation of simulated prostate gland lesions in a preclinical canine model. To correlate ablation volumes measured with intra-procedural cumulative thermal damage estimates, post-procedural MRI, and histopathology.

MATERIALS AND METHODS

Three dogs were treated with three targeted ablations each, using a prototype MRI-guided transurethral US-therapy system (Philips Healthcare, Vantaa, Finland). MRI provided images for treatment planning, guidance, real-time multi-planar thermometry, as well as post-treatment evaluation of efficacy. After treatment, specimens underwent histopathological analysis to determine the extent of necrosis and cell viability. Statistical analyses (Pearson's correlation, Student's t-test) were used to evaluate the correlation between ablation volumes measured with intra-procedural cumulative thermal damage estimates, post-procedural MRI, and histopathology.

RESULTS

MRI combined with a transurethral US-therapy device enabled multi-planar temperature monitoring at the target as well as in surrounding tissues, allowing for safe, targeted, and controlled ablations of prescribed lesions. Ablated volumes measured by cumulative thermal dose positively correlated with volumes determined by histopathological analysis (r(2) 0.83, P < 0.001). Post-procedural contrast-enhanced and diffusion-weighted MRI showed a positive correlation with non-viable areas on histopathological analysis (r(2) 0.89, P < 0.001, and r(2) 0.91, P = 0.003, respectively). Additionally, there was a positive correlation between ablated volumes according to cumulative thermal dose and volumes identified on post-procedural contrast-enhanced MRI (r(2) 0.77, P < 0.01). There was no difference in mean ablation volumes assessed with the various analysis methods (P > 0.05, Student's t-test).

CONCLUSIONS

MRI-guided transurethral US therapy enabled safe and targeted ablations of prescribed lesions in a preclinical canine prostate model. Ablation volumes were reliably predicted by intra- and post-procedural imaging. Clinical studies are needed to confirm the feasibility, safety, oncological control, and functional outcomes of this therapy in patients in whom focal therapy is indicated.

Phase II trial of vandetanib in Von Hippel-Lindau-associated renal cell carcinoma

4584

Background: Germline mutations in the von Hippel Lindau (VHL) gene are associated with the development of bilateral multifocal clear-cell renal cell carcinoma (RCC). VHL patients with localized disease are surgically managed, with nephron sparing resection recommended once tumors reach 3 cm. Patients typically undergo multiple surgeries with significant cumulative morbidity. In this phase 2 trial of vandetanib, a dual VEGFR2/EGFR inhibitor, a systemic approach to these tumors was explored. Methods: Patients with VHL-associated RCC were treated with 300 mg vandetanib daily until disease progression or unacceptable toxicity. Cross sectional imaging was performed at baseline and every 12 weeks. The primary endpoint was overall renal tumor response assessed by RECIST. Results: A total of 34 subjects were enrolled, with a mean age of 47 years (range 28 – 72). The median number of targeted lesions per subject was 2 (range 1 – 6) and the mean tumor diameter was 2.3 cm (range 1.2 – 4.0). Twenty-seven (80%) subjects had baseline imaging and at least one follow-up study to allow response evaluation. Median time on study was 6.1 months (range 1.0 – 23.3). Thirteen (38%) subjects demonstrated overall reduction in tumor burden with a median reduction of 6% (range 4-54%). One (3%) subject had a PR by RECIST and 26 (77%) had stable disease as their best response. Eleven (32%) subjects were taken off study due to growth of at least one lesion that met criteria for surgical resection or disease progression. Nine (27%) subjects required dose reductions due to toxicity. Although the majority of adverse events encountered on trial were grade 2 or less, 9 (27%) subjects were taken off trial due to drug-related toxicities and 9 (27%) withdrew due to intolerable side effects. Rash (71%), and QTc prolongation (41%) were the most common adverse events noted. Conclusions: In the largest phase II study of a systemic agent for VHL-related RCC, vandetanib demonstrated anti-tumor activity. Despite a reasonable safety profile, poor tolerability necessitated drug withdrawal in a significant proportion of patients. Newer agents that selectively target the VEGF receptors may offer a more tolerable alternative and might optimize clinical benefits in this population. Clinical trial information: NCT0056695.

Perioperative management of radical cystectomy patients: A questionnaire survey of the American Urological Association members

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Background: Radical cystectomy (RC) is the standard treatment for patients with muscle invasive bladder cancer. RC is associated with more post-op complications and longer length of stay (LOS) after surgery than other urologic procedures. There is little information about peri-op pathways in the urologic literature. This study investigates practice patterns of urologists in the United States on peri-op management of bladder cancer patients undergoing RC. Methods: All AUA members were invited via email to an online survey from April to August 2012. The 31-items questionnaire of multiple choice and open-ended questions related to training, practice, and peri-op protocols. Results: A total of 375 urologists participated in the survey, 28.9% have oncology fellowship training, 46.4% training in robotic RC, and 30.1% perform robotics or laparoscopy. Of participants, 41.6% follow a clinical pathway however most utilize experience/training rather than an evidence-based protocol. Even with current evidence for enhanced recovery after surgery (ERAS) only 39.5% of respondents perform pre-op nutritional assessment. Most require a prolonged fast, no carbohydrate loading, and give all patients bowel prep pre-op. Most administer antibiotic prophylaxis before incision and continued 24 hrs, however only ~1/3 administer thromboprophylaxis pre-op, 15% give neither pre or post-op. Of respondents only 5% initiate a diet on post-op day (POD) 1 or before. 38.6% routinely send patients to ICU after surgery. Epidural, narcotics, or NSAIDs are commonly used for pain control, narcotics being the most common. Overall first flatus is reported on POD3 to 4, first bowel movement on POD4 to 5. Most patients are discharged on POD6 to 7. Urologists with oncology fellowship stated shorter LOS compared to those without (POD6.19 vs 6.64). Those doing open RC stated longer LOS compared to those doing robotic or laparoscopic RC (POD6.54 vs 6.03). Conclusions: ERAS studies have shown objective parameters that can improve peri-op outcomes. However, this survey shows significant individual differences in peri-op management of bladder cancer with the majority of urologists using personal experience as their primary guide.

Low suspicion lesions on multiparametric magnetic resonance imaging predict for the absence of high-risk prostate cancer

What's known on the subject? and What does the study add? Over-treatment of indolent prostate cancer lesions is a problem which can result in increased human and medical costs. Lesions with a low suspician level at mpMRI of the prostate have low risk of including high risk prostate cancer.

OBJECTIVE

To determine whether multiparametric magnetic resonance imaging (mpMRI) has the potential to identify patients at low risk for cancer, thus obviating the need for biopsy. Prostate cancer is currently diagnosed by random biopsies, resulting in the discovery of multiple low-risk cancers that often lead to overtreatment.

PATIENTS AND METHODS

We reviewed 800 consecutive patients who underwent a 3 Tesla mpMRI of the prostate with an endorectal coil from March 2007 to November 2011. All suspicious lesions were independently reviewed by two radiologists using T2-weighted, diffusion-weighted, spectroscopic and dynamic contrast-enhanced MRI sequences. Patients with only low suspicion lesions (maximum of two positive parameters on mpMRI) who subsequently underwent transrectal ultrasonography (TRUS)/MRI fusion targeted biopsy were selected for analysis.

RESULTS

In total, 125 patients with only low suspicion prostatic lesions on mpMRI were identified. On TRUS/MRI fusion biopsy, 77 (62%) of these patients had no cancer detected, 38 patients had Gleason 6 disease and 10 patients had Gleason 7 (3+4) disease. There were 30 patients with cancer detected on biopsy who qualified for active surveillance using 2011 National Comprehensive Cancer Network guidelines. No cases of high-risk (≥ Gleason 4+3) cancer were identified on biopsy and, of the fifteen patients who underwent radical prostatectomy at our institution, none were pathologically upgraded to high-risk cancer. Thus, for patients with only low suspicion lesions, 107 (88%) patients either had no cancer or clinically insignificant disease.

CONCLUSIONS

The results obtained in the present study show that low suspicion lesions on mpMRI are associated with either negative biopsies or low-grade tumours suitable for active surveillance. Such patients have a low risk of harbouring high-risk prostate cancers.

Multiparametric magnetic resonance imaging and ultrasound fusion biopsy detect prostate cancer in patients with prior negative transrectal ultrasound biopsies

PURPOSE

Patients with negative transrectal ultrasound biopsies and a persistent clinical suspicion are at risk for occult but significant prostate cancer. The ability of multiparametric magnetic resonance imaging/ultrasound fusion biopsy to detect these occult prostate lesions may make it an effective tool in this challenging scenario.

MATERIALS AND METHODS

Between March 2007 and November 2011 all men underwent prostate 3 T endorectal coil magnetic resonance imaging. All concerning lesions were targeted with magnetic resonance imaging/ultrasound fusion biopsy. In addition, all patients underwent standard 12-core transrectal ultrasound biopsy. Men with 1 or more negative systematic prostate biopsies were included in our cohort.

RESULTS

Of the 195 men with previous negative biopsies, 73 (37%) were found to have cancer using the magnetic resonance imaging/ultrasound fusion biopsy combined with 12-core transrectal ultrasound biopsy. High grade cancer (Gleason score 8+) was discovered in 21 men (11%), all of whom had disease detected with magnetic resonance imaging/ultrasound fusion biopsy. However, standard transrectal ultrasound biopsy missed 12 of these high grade cancers (55%). Pathological upgrading occurred in 28 men (38.9%) as a result of magnetic resonance imaging/ultrasound fusion targeting vs standard transrectal ultrasound biopsy. The diagnostic yield of combined magnetic resonance imaging/ultrasound fusion platform was unrelated to the number of previous negative biopsies and persisted despite increasing the number of previous biopsy sessions. On multivariate analysis only prostate specific antigen density and magnetic resonance imaging suspicion level remained significant predictors of cancer.

CONCLUSIONS

Multiparametric magnetic resonance imaging with a magnetic resonance imaging/ultrasound fusion biopsy platform is a novel diagnostic tool for detecting prostate cancer and may be ideally suited for patients with negative transrectal ultrasound biopsies in the face of a persistent clinical suspicion for cancer.

Structure of MurA (UDP-N-acetylglucosamine enolpyruvyl transferase) from Vibrio fischeri in complex with substrate UDP-N-acetylglucosamine and the drug fosfomycin

The development of new antibiotics is necessitated by the rapid development of resistance to current therapies. UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), which catalyzes the first committed step of bacterial peptidoglycan biosynthesis, is a prime candidate for therapeutic intervention. MurA is the target of the antibiotic fosfomycin, a natural product produced by Streptomyces. Despite possessing a high degree of sequence conservation with MurA enzymes from fosfomycin-susceptible organisms, recent microbiological studies suggest that MurA from Vibrio fischeri (VfiMurA) may confer fosfomycin resistance via a mechanism that is not yet understood. The crystal structure of VfiMurA in a ternary complex with the substrate UDP-N-acetylglucosamine (UNAG) and fosfomycin has been solved to a resolution of 1.93 Å. Fosfomycin is known to inhibit MurA by covalently binding to a highly conserved cysteine in the active site of the enzyme. A comparison of the title structure with the structure of fosfomycin-susceptible Haemophilus influenzae MurA (PDB entry 2rl2) revealed strikingly similar conformations of the mobile substrate-binding loop and clear electron density for a fosfomycin-cysteine adduct. Based on these results, there are no distinguishing sequence/structural features in VfiMurA that would translate to a diminished sensitivity to fosfomycin. However, VfiMurA is a robust crystallizer and shares high sequence identity with many clinically relevant bacterial pathogens. Thus, it would serve as an ideal system for use in the structure-guided optimization of new antibacterial agents.

Search for a light pseudoscalar particle in the decay K_{L};{0}-->pi;{0}pi;{0}X

We performed a search for a light pseudoscalar particle X in the decay K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma with the E391a detector at KEK. Such a particle with a mass of 214.3 MeV/c;{2} was suggested by the HyperCP experiment. We found no evidence for X and set an upper limit on the product branching ratio for K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma of 2.4x10;{-7} at the 90% confidence level. Upper limits on the branching ratios in the mass region of X from 194.3 to 219.3 MeV/c;{2} are also presented.

Search for the Decay K L0-->pi0nu nu[over]

We performed a search for the K L0-->pi0nu nu[over] decay at the KEK 12-GeV proton synchrotron. No candidate events were observed. An upper limit on the branching ratio for the decay was set to be 6.7 x 10(-8) at the 90% confidence level.