Diagnostic accuracy and clinical impact of renal biopsy cytology.

BACKGROUND: The role of fine needle biopsy cytology in the workup of renal mass lesions remains controversial. With advances in imaging technology and clinical management for renal masses, a critical reevaluation of the role of renal biopsy is needed. This study was designed to provide a comprehensive evaluation of the performance and clinical impact of fine needle biopsy in patients with renal masses. METHODS: A 5-year retrospective study of ultrasound or computer tomography (CT)-guided fine needle biopsies of renal masses diagnosed via cytopathology was conducted. Overall diagnostic rate, sensitivity, and diagnostic accuracy were calculated. Further analysis of the impact of fine needle biopsy cytology on clinical management was performed. RESULTS: A total of 227 cases of fine-needle aspiration and/or biopsy (FNA/B) of renal masses were identified, including 76 with subsequent nephrectomies. Complications were rare (<1%). The diagnostic rate and sensitivity of FNA/B were 83.3% and 89.5%, respectively. Diagnostic accuracy was 98.7% at the major categorical level and 94.7% at the tumor subtype level. Subsequent clinical actions were associated with a definitive cytologic diagnosis of malignancy/neoplasia (p < .05) and were affected by tumor subtype (p < .05). CONCLUSION: This study demonstrates that FNA/B of renal masses is a safe and reliable minimally invasive diagnostic tool with excellent accuracy in confirmation of malignancy and subclassification of tumors. Diagnoses made on FNA/B play a key role in guiding a personalized clinical treatment plan.

Pathologist-performed ultrasound-guided fine needle aspiration biopsies of extrathyroidal sites: An observational study.

BACKGROUND: Pathologist-performed ultrasound-guided fine needle aspiration (USFNA) biopsies have become an increasingly important component of the interventional cytopathologist's toolbox. However, its application varies between institutions, and there is limited literature describing its performance characteristics when utilized in extrathyroidal sites. Here we review our institutional experience within our pathologist-run FNA clinic. METHODS: A retrospective review was conducted of pathologist-performed USFNAs of extrathyroidal sites over a 9-year period. Data collected included lesion site, size, patient age, patient gender, diagnostic category, and corresponding results from surgical resection when available. The diagnosis on surgical resection was considered the gold standard for determining discordance rates. RESULTS: A total of 143 pathologist-performed USFNAs of extrathyroidal lesions were performed from October 2011 to October 2020. These encompassed a wide range of sites, with most biopsies from the head and neck. The mean recorded size was 2.2 cm, with a range of 0.6-6 cm. Larger lesions (over 2 cm) were more likely to be noted in challenging locations, demonstrate difficult features, or be cystic. Most (n = 133) biopsies were sufficient for diagnosis, with a non-diagnostic rate of 7% (n = 10). Accuracy when compared to subsequent surgical resection was high, with sensitivity of 89%, specificity of 93%, positive predictive value of 94%, and negative predictive value of 87%. CONCLUSION: Our experience supports that pathologist-performed USFNA of extrathyroidal lesions-even those with challenging features-can result in excellent diagnostic yield and accuracy. The addition of USFNA to the interventional cytopathologists' repertoire can be a valuable tool to enhance patient care.

Structured approach to resolving discordance between PI-RADS v2.1 score and targeted prostate biopsy results: an opportunity for quality improvement.

BACKGROUND: Prostate multiparametric magnetic resonance imaging (mpMRI) can identify lesions within the prostate with characteristics identified in Prostate Imaging Reporting and Data System (PI-RADS) v2.1 associated with clinically significant prostate cancer (csPCa) or Gleason grade group (GGG) ≥ 2 at biopsy. OBJECTIVE: To assess concordance (PI-RADS 5 lesions with csPCa) of PI-RADS v2/2.1 with targeted, fusion biopsy results and to examine causes of discordance (PI-RADS 5 lesions without csPCa) with aim to provide a structured approach to resolving discordances and develop quality improvement (QI) protocols. METHODS: A retrospective study of 392 patients who underwent mpMRI at 3 Tesla followed by fusion biopsy. PI-RADS v2/2.1 scores were assigned to lesions identified on mpMRI and compared to biopsy results expressed as GGG. Positive predictive value (PPV) of PI-RADS v2/2.1 was calculated for all prostate cancer and csPCa. Discordant cases were re-reviewed by a radiologist with expertise in prostate mpMRI to determine reason for discordance. RESULTS: A total of 521 lesions were identified on mpMRI. 121/521 (23.2%), 310/524 (59.5%), and 90/521 (17.3%) were PI-RADS 5, 4, and 3, respectively. PPV of PI-RADS 5, 4, and 3 for all PCa and csPCa was 0.80, 0.55, 0.24 and 0.63, 0.33, and 0.09, respectively. 45 cases of discordant biopsy results for PI-RADS 5 lesions were found with 27 deemed "true" discordances or "unresolved" discordances where imaging re-review confirmed PI-RADS appropriateness, while 18 were deemed "false" or resolved discordances due to downgrading of PI-RADS scores based on imaging re-review. Adjusting for resolved discordances on re-review, the PPV of PI-RADS 5 lesions for csPCa was deemed to be 0.74 and upon adjusting for presence of csPCa found in cases of unresolved discordance, PPV rose to 0.83 for PI-RADS 5 lesions. CONCLUSION: Although PIRADS 5 lesions are considered high risk for csPCa, the PPV is not 100% and a diagnostic dilemma occurs when targeted biopsy returns discordant. While PI-RADS score is downgraded in some cases upon imaging re-review, a number of "false" or "unresolved" discordances were identified in which MRI re-review confirmed initial PI-RADS score and subsequent pathology confirmed presence of csPCa in these lesions. CLINICAL IMPACT: We propose a structured approach to resolving discordant biopsy results using multi-disciplinary re-review of imaging and archived biopsy strikes as a quality improvement pathway. Further work is needed to determine the value of re-biopsy in cases of unresolved discordance and to develop robust QI systems for prostate MRI.

Pathologist-performed ultrasound-guided fine-needle aspirations of the thyroid: A single institution observational study.

BACKGROUND: Ultrasound-guided fine-needle aspiration biopsies (USFNAs) are increasingly performed by pathologists. This study was designed to assess the diagnostic yield and characterization of thyroid nodules biopsied at a teaching hospital setting in which both attending physicians and trainees are involved in the performance of USFNAs. METHODS: A retrospective study of pathologist-performed USFNAs of thyroid cases was performed over a period of 9 years at a tertiary medical center. Data collected included patient characteristics and The Bethesda System diagnostic categories. RESULTS: Over the study period, 1531 USFNAs of thyroid nodules were performed in the pathology-based clinic, with 1209 lesions in females and 322 in males. Ninety-three percent of samples were sufficient for diagnosis (n = 1420). The majority of nodules biopsied were benign (65.4%, n = 1002). Overall, 3.1% of nodules biopsied were diagnostic of malignancy (n = 47). The number of USFNAs over the years showed a rapid increase initially, with a coronavirus disease 2019-related decrease in 2020. CONCLUSIONS: The authors report their experience with thyroid USFNA over nearly a decade. The most common diagnosis was benign and the second most common was Bethesda category III. Lesions that were diagnostic of malignancy were relatively uncommon. Over the study period, the results showed that at a large tertiary care center in which USFNAs were performed by trainees as well as attending physicians, the diagnostic yield was good with a majority of thyroid nodules biopsied associated with a definitive diagnosis.

Teaching interventional cytopathology.

Interventional cytopathology is a unique area of pathology, where cytopathologists play a primary role in obtaining fine needle aspiration biopsies and/or making determinations through rapid on-site evaluations to guide sample procurement in real-time. Unsurprisingly, experience and skill are directly related to success in these endeavors, and both can be fostered with formal instruction. There is a wealth of resources available to aid in teaching interventional cytopathology, including instructional videos, courses, and model phantoms which can help to build familiarity and confidence. These tools can provide a basic framework upon which skills can be developed through in-person guidance, real-time feedback and practice. This article reviews the tools available to enhance training, details the authors' institutional experience in teaching interventional cytopathology at a tertiary care center, and provides recommendations and pearls for success in this endeavor.

A Hybrid Human-Machine Learning Approach for Screening Prostate Biopsies Can Improve Clinical Efficiency Without Compromising Diagnostic Accuracy.

CONTEXT.­: Prostate cancer is a common malignancy, and accurate diagnosis typically requires histologic review of multiple prostate core biopsies per patient. As pathology volumes and complexity increase, new tools to improve the efficiency of everyday practice are keenly needed. Deep learning has shown promise in pathology diagnostics, but most studies silo the efforts of pathologists from the application of deep learning algorithms. Very few hybrid pathologist-deep learning approaches have been explored, and these typically require complete review of histologic slides by both the pathologist and the deep learning system. OBJECTIVE.­: To develop a novel and efficient hybrid human-machine learning approach to screen prostate biopsies. DESIGN.­: We developed an algorithm to determine the 20 regions of interest with the highest probability of malignancy for each prostate biopsy; presenting these regions to a pathologist for manual screening limited the initial review by a pathologist to approximately 2% of the tissue area of each sample. We evaluated this approach by using 100 biopsies (29 malignant, 60 benign, 11 other) that were reviewed by 4 pathologists (3 urologic pathologists, 1 general pathologist) using a custom-designed graphical user interface. RESULTS.­: Malignant biopsies were correctly identified as needing comprehensive review with high sensitivity (mean, 99.2% among all pathologists); conversely, most benign prostate biopsies (mean, 72.1%) were correctly identified as needing no further review. CONCLUSIONS.­: This novel hybrid system has the potential to efficiently triage out most benign prostate core biopsies, conserving time for the pathologist to dedicate to detailed evaluation of malignant biopsies.

Characterization of a castrate-resistant prostate cancer xenograft derived from a patient of West African ancestry.

BACKGROUND: Prostate cancer is a clinically and molecularly heterogeneous disease, with highest incidence and mortality among men of African ancestry. To date, prostate cancer patient-derived xenograft (PCPDX) models to study this disease have been difficult to establish because of limited specimen availability and poor uptake rates in immunodeficient mice. Ancestrally diverse PCPDXs are even more rare, and only six PCPDXs from self-identified African American patients from one institution were recently made available. METHODS: In the present study, we established a PCPDX from prostate cancer tissue from a patient of estimated 90% West African ancestry with metastatic castration resistant disease, and characterized this model's pathology, karyotype, hotspot mutations, copy number, gene fusions, gene expression, growth rate in normal and castrated mice, therapeutic response, and experimental metastasis. RESULTS: This PCPDX has a mutation in TP53 and loss of PTEN and RB1. We have documented a 100% take rate in mice after thawing the PCPDX tumor from frozen stock. The PCPDX is castrate- and docetaxel-resistant and cisplatin-sensitive, and has gene expression patterns associated with such drug responses. After tail vein injection, the PCPDX tumor cells can colonize the lungs of mice. CONCLUSION: This PCPDX, along with others that are established and characterized, will be useful pre-clinically for studying the heterogeneity of prostate cancer biology and testing new therapeutics in models expected to be reflective of the clinical setting.

Tissue based biomarkers in non-clear cell RCC: Correlative analysis from the ASPEN clinical trial.

Biomarkers are needed in patients with non-clear cell renal cell carcinomas (NC-RCC), particularly papillary renal cell carcinoma, in order to inform on initial treatment selection and identify potentially novel targets for therapy. We enrolled 108 patients in ASPEN, an international randomized open-label phase 2 trial of patients with metastatic papillary, chromophobe, or unclassified NC-RCC treated with the mTOR inhibitor everolimus (n=57) or the vascular endothelial growth factor (VEGF) receptor inhibitor sunitinib (n=51), stratified by MSKCC risk and histology. The primary endpoint was overall survival (OS) and secondary efficacy endpoints for this exploratory biomarker analysis were radiographic progression-free survival (rPFS) defined by intention-to-treat using the RECIST 1.1 criteria and radiographic response rates. Tissue biomarkers (n=78) of mTOR pathway activation (phospho-S6 and -Akt, c-kit) and VEGF pathway activation (HIF-1α, c-MET) were prospectively explored in tumor tissue by immunohistochemistry prior to treatment and associated with clinical outcomes. We found that S6 activation was more common in poor risk NC-RCC tumors and S6/Akt activation was associated with worse PFS and OS outcomes with both everolimus and sunitinib, while c-kit was commonly expressed in chromophobe tumors and associated with improved outcomes with both agents. C-MET was commonly expressed in papillary tumors and was associated with lower rates of radiographic response but did not predict PFS for either agent. In multivariable analysis, both pAkt and c-kit were statistically significant prognostic biomarkers of OS. No predictive biomarkers of treatment response were identified for clinical outcomes. Most biomarker subgroups had improved outcomes with sunitinib as compared to everolimus.

Prostate Cancer Detection Using 3-D Shear Wave Elasticity Imaging.

Transrectal ultrasound (TRUS) B-mode imaging provides insufficient sensitivity and specificity for prostate cancer (PCa) targeting when used for biopsy guidance. Shear wave elasticity imaging (SWEI) is an elasticity imaging technique that has been commercially implemented and is sensitive and specific for PCa. We have developed a SWEI system capable of 3-D data acquisition using a dense acoustic radiation force (ARF) push approach that leads to enhanced shear wave signal-to-noise ratio compared with that of the commercially available SWEI systems and facilitates screening of the entire gland before biopsy. Additionally, we imaged and assessed 36 patients undergoing radical prostatectomy using 3-D SWEI and determined a shear wave speed threshold separating PCa from healthy prostate tissue with sensitivities and specificities akin to those for multiparametric magnetic resonance imaging fusion biopsy. The approach measured the mean shear wave speed in each prostate region to be 4.8 m/s (Young's modulus E = 69.1 kPa) in the peripheral zone, 5.3 m/s (E = 84.3 kPa) in the central gland and 6.0 m/s (E = 108.0 kPa) for PCa with statistically significant (p < 0.0001) differences among all regions. Three-dimensional SWEI receiver operating characteristic analyses identified a threshold of 5.6 m/s (E = 94.1 kPa) to separate PCa from healthy tissue with a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) of 81%, 82%, 69%, 89% and 0.84, respectively. Additionally, a shear wave speed ratio was assessed to normalize for tissue compression and patient variability, which yielded a threshold of 1.11 to separate PCa from healthy prostate tissue and was accompanied by a substantial increase in specificity, PPV and AUC, where the sensitivity, specificity, PPV, NPV and AUC were 75%, 90%, 79%, 88% and 0.90, respectively. This work illustrates the feasibility of using 3-D SWEI data to detect and localize PCa and demonstrates the benefits of normalizing for applied compression during data acquisition for use in biopsy targeting studies.

Evaluation of pelvic washing specimens in patients with endometrial cancer: Cytomorphological features, diagnostic agreement, and pathologist experience.

BACKGROUND: Pelvic washings for patients with endometrial cancer is recommended but not used for staging. The International System for Reporting Serous Fluid Cytology (TIS) has standardized diagnostic categories, but the criteria remain incomplete. The 3 primary goals of this study were to 1) investigate features that distinguish atypical/indeterminate from malignant specimens, 2) measure the level of agreement between chart and reviewer diagnoses, and 3) determine whether the number of years in practice had an effect on the diagnoses rendered. METHODS: Pelvic washings and surgical pathology specimens for 52 patients with a chart diagnosis of atypical/indeterminate, suspicious, or malignant cytology and 52 age-matched controls with a negative chart diagnosis were included, reviewed blindly by 2 cytopathologists, and assigned a study diagnosis. Morphologic features were assessed. Agreement between original chart diagnoses and reviewer diagnoses were assessed as well as effect of years in practice. RESULTS: The overall cellularity in cell block (CB) slides for the malignant category was significantly increased compared with the atypical/indeterminate category (P < .0001). In addition, the number of atypical groups in ThinPrep for malignant washings was significantly increased compared with the atypical category (P < .001) and the negative and suspicious categories (P < .0001) in the CB. Overall agreement between the original and adjudicated diagnoses was high (γ = 0.983). There was no significant difference between diagnoses rendered and years in practice. CONCLUSION: The overall cellularity and number of atypical cells can be used to distinguish between malignant and atypical pelvic washing specimens. There is high reproducibility in the diagnostic categories and high agreement among pathologists, regardless of practice experience. These findings can help refine the criteria for TIS.

Clinicopathological features to distinguish malignant solitary fibrous tumors of the prostate from prostatic stromal tumors.

Mesenchymal tumors of the prostate are rare but encompass a wide differential diagnosis. In our study, we aimed to investigate the clinicopathological features that can be used to differentiate malignant solitary fibrous tumors (mSFTs) occurring in the prostate from prostatic stromal tumors. A total of 15 patients with mesenchymal tumors of the prostate were identified in Nanjing Drum Tower Hospital from 2009 to 2019, including 3 mSFTs, 9 stromal tumors of uncertain malignant potential (STUMPs), and 3 prostatic stromal sarcomas (PSSs). Immunohistochemical stains for signal transducer and activator of transcription 6 (STAT6), aldehyde dehydrogenase 1 (ALDH1), CD34, desmin, smooth muscle actin (SMA), progesterone receptor (PR), CD117, and cytokeratin (CK) were performed on representative sections from each tumor, and the clinical features, histology, and immunophenotype of these three groups were analyzed. There was no significant difference in mean patient age of patients diagnosed with mSFTs, STUMPs, and PSSs. mSFTs and PSSs showed significantly increased tumor size (p < 0.05), Ki-67 proliferation index (p < 0.0001), and mitotic activity (p < 0.05) when compared with STUMPs. mSFTs showed significantly higher expression of STAT6 compared with both PSSs and STUMPs (p < 0.0001, p < 0.0001). PR showed significantly more expression in STUMPs than in mSFTs or PSSs (p < 0.0001, p < 0.0001). Desmin and SMA showed significantly more expression in STUMPs than in mSFTs (p < 0.05). ALDH1, CD117, CK, and CD34 showed no significant difference in staining between mSFTs, STUMPs, and PSSs. Therefore, a limited panel of STAT6, PR, and Ki-67 may be useful in distinguishing between mSFTs, STUMPs, and PSSs.

Multiparametric Ultrasound for Targeting Prostate Cancer: Combining ARFI, SWEI, QUS and B-Mode.

Diagnosing prostate cancer through standard transrectal ultrasound (TRUS)-guided biopsy is challenging because of the sensitivity and specificity limitations of B-mode imaging. We used a linear support vector machine (SVM) to combine standard TRUS imaging data with acoustic radiation force impulse (ARFI) imaging data, shear wave elasticity imaging (SWEI) data and quantitative ultrasound (QUS) midband fit data to enhance lesion contrast into a synthesized multiparametric ultrasound volume. This SVM was trained and validated using a subset of 20 patients and tested on a second subset of 10 patients. Multiparametric US led to a statistically significant improvements in contrast, contrast-to-noise ratio (CNR) and generalized CNR (gCNR) when compared with standard TRUS B-mode and SWEI; in contrast and CNR when compared with MF; and in CNR when compared with ARFI. ARFI, MF and SWEI also outperformed TRUS B-mode in contrast, with MF outperforming B-mode in CNR and gCNR as well. ARFI, although only yielding statistically significant differences in contrast compared with TRUS B-mode, captured critical qualitative features for lesion identification. Multiparametric US enhanced lesion visibility metrics and is a promising technique for targeted TRUS-guided prostate biopsy in the future.

PD-L1 Assay Concordance in Metastatic Renal Cell Carcinoma and Metastatic Urothelial Carcinoma.

BACKGROUND: Immune checkpoint inhibitors are now standard of care for many patients with metastatic renal cell carcinoma (mRCC) and metastatic urothelial carcinoma (mUC). Given real-world limitations in programmed death-ligand 1 (PD-L1) testing, concordance studies between PD-L1 assays are needed. We undertook comparisons of Dako 28-8 and Ventana SP142 assays in mRCC and Dako 22C3 and Ventana SP263 assays in mUC. PATIENTS AND METHODS: Thirty-two patients with mRCC and 18 patients with mUC who had received immune checkpoint inhibitor therapy were identified. Formalin-fixed paraffin-embedded tumor samples for patients with mRCC were evaluated with Dako 28-8 and Ventana SP142 PD-L1 immunohistochemistry assays. For patients with mUC, formalin-fixed paraffin-embedded tumor samples were evaluated with Dako 22C3 and Ventana SP263 PD-L1 immunohistochemistry assays. RESULTS: The majority (29/32; 91%) of mRCC cases were concordant between assays. The majority (17/18; 94%) of mUC cases were also concordant between assays. CONCLUSIONS: There was strong concordance between PD-L1 assays chosen for comparison in both mRCC and mUC, with similar performance characteristics. One limitation is the small number of cases in this study; larger comparison studies are needed for this biomarker in mRCC and mUC.

High-risk and intermediate-high-risk results from the ThyroSeq v2 and v3 thyroid genomic classifier are associated with neoplasia: Independent performance assessment at an academic institution.

BACKGROUND: The ThyroSeq panel tests for genetic alterations to risk-stratify cytologically indeterminate nodules. The authors assessed the test performance of the tests, including the latest version (v3), at an academic center. METHODS: Results from ThyroSeq testing (v2 and v3) were reviewed over 2 years, and patient demographics, cytology diagnoses, results of ThyroSeq testing, and histopathologic diagnoses on resection (if available) were collected. RESULTS: One hundred eighty-five nodules were tested from 178 patients, including 94 nodules tested with v2 and 91 nodules tested with v3. Overall, 28 of 185 nodules (15%) yielded a high-risk or intermediate-high-risk mutation (HRM). Of the patients with these nodules, 19 of 25 (76%) had neoplastic nodules, and 11 of 25 (44%) had a malignancy or a noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Only 16 of 147 nodules (11%) that were negative or had low-risk genetic alterations underwent resection, with 1 false-negative result (a papillary thyroid carcinoma tested with v2). No false-negative results were identified with v3. Two nodules had TP53 mutations identified, both of which were benign on resection. Nodules with HRM that were tested with v2 and v3 had a positive predictive value (PPV) for malignancy of 57% and 39%, respectively, and a PPV for neoplasm of 86% and 72%, respectively. The negative predictive values for v2 and v3 were 92% and 100%, respectively. CONCLUSIONS: The PPV of an HRM result on ThyroSeq v3 was low for malignancy or NIFTP, and the PPV for neoplasm was higher. RAS-type mutations were the most commonly identified in both benign and malignant nodules. Thyroseq v3 had a lower PPV for both malignancy/NIFTP and neoplasm than v2 but did not produce any false-negative results.

Metastatic Urothelial Carcinoma from Transplanted Kidney with Complete Response to an Immune Checkpoint Inhibitor.

BACKGROUND: Donor-derived malignancy is a rare complication in patients who undergo organ transplant. Approaches to treatment have largely been individualized based on clinical circumstances given the lack of evidence-based guidelines, with therapeutic options ranging from discontinuation of immunosuppression and transplantectomy to the addition of chemotherapy or radiotherapy. Case Presentation. Herein, we describe a 60-year-old woman with metastatic donor-derived upper tract urothelial carcinoma (UTUC) discovered nine years postrenal transplant. Molecular diagnostic studies using polymerase chain reaction amplification of short tandem repeat alleles and HLA tissue typing proved that the urothelial carcinoma originated from donor tissue. She achieved sustained complete remission with transplant nephroureterectomy, retroperitoneal lymphadenectomy, immunosuppression withdrawal, and immunotherapy with pembrolizumab. Routine radiologic surveillance has demonstrated 15-month progression-free survival to date off pembrolizumab, and she is now under consideration for retransplantation. CONCLUSIONS: Immunotherapy using checkpoint inhibitors can serve as a novel treatment option for patients in the clinical predicament of having a solid organ transplant and simultaneous metastatic malignancy. In this report, we also discuss the oncogenic potential of BK virus, the use of checkpoint inhibitors in urothelial carcinoma, and the feasibility of retransplant for this patient population.

Discordant and heterogeneous clinically relevant genomic alterations in circulating tumor cells vs plasma DNA from men with metastatic castration resistant prostate cancer.

Circulating tumor cell (CTC) and cell-free (cf) DNA-based genomic alterations are increasingly being used for clinical decision-making in oncology. However, the concordance and discordance between paired CTC and cfDNA genomic profiles remain largely unknown. We performed comparative genomic hybridization (CGH) on CTCs and cfDNA, and low-pass whole genome sequencing (lpWGS) on cfDNA to characterize genomic alterations (CNA) and tumor content in two independent prospective studies of 93 men with mCRPC treated with enzalutamide/abiraterone, or radium-223. Comprehensive analysis of 69 patient CTCs and 72 cfDNA samples from 93 men with mCRPC, including 64 paired samples, identified common concordant gains in FOXA1, AR, and MYC, and losses in BRCA1, PTEN, and RB1 between CTCs and cfDNA. Concordant PTEN loss and discordant BRCA2 gain were associated with significantly worse outcomes in Epic AR-V7 negative men with mCRPC treated with abiraterone/enzalutamide. We identified and externally validated CTC-specific genomic alternations that were discordant in paired cfDNA, even in samples with high tumor content. These CTC/cfDNA-discordant regions included key genomic regulators of lineage plasticity, osteomimicry, and cellular differentiation, including MYCN gain in CTCs (31%) that was rarely detected in cfDNA. CTC MYCN gain was associated with poor clinical outcomes in AR-V7 negative men and small cell transformation. In conclusion, we demonstrated concordance of multiple genomic alterations across CTC and cfDNA platforms; however, some genomic alterations displayed substantial discordance between CTC DNA and cfDNA despite the use of identical copy number analysis methods, suggesting tumor heterogeneity and divergent evolution associated with poor clinical outcomes.

Correction to: N-Myc promotes therapeutic resistance development of neuroendocrine prostate cancer by differentially regulating miR-421/ ATM pathway.

Following publication of the original article [1], the authors reported that name that appeared in published online version is incorrect. Aifeng Wang should be Aifen Wang. Corrected name is provided in the author group section above.

Pharmacodynamic study of radium-223 in men with bone metastatic castration resistant prostate cancer.

BACKGROUND: Radium-223 is a targeted alpha-particle therapy that improves survival in men with metastatic castration resistant prostate cancer (mCRPC), particularly in men with elevated serum levels of bone alkaline phosphatase (B-ALP). We hypothesized that osteomimicry, a form of epithelial plasticity leading to an osteoblastic phenotype, may contribute to intralesional deposition of radium-223 and subsequent irradiation of the tumor microenvironment. METHODS: We conducted a pharmacodynamic study (NCT02204943) of radium-223 in men with bone mCRPC. Prior to and three and six months after radium-223 treatment initiation, we collected CTCs and metastatic biopsies for phenotypic characterization and CTC genomic analysis. The primary objective was to describe the impact of radium-223 on the prevalence of CTC B-ALP over time. We measured radium-223 decay products in tumor and surrounding normal bone during treatment. We validated genomic findings in a separate independent study of men with bone metastatic mCRPC (n = 45) and publicly accessible data of metastatic CRPC tissues. RESULTS: We enrolled 20 men with symptomatic bone predominant mCRPC and treated with radium-223. We observed greater radium-223 radioactivity levels in metastatic bone tumor containing biopsies compared with adjacent normal bone. We found evidence of persistent Cellsearch CTCs and B-ALP (+) CTCs in the majority of men over time during radium-223 therapy despite serum B-ALP normalization. We identified genomic gains in osteoblast mimicry genes including gains of ALPL, osteopontin, SPARC, OB-cadherin and loss of RUNX2, and validated genomic alterations or increased expression at the DNA and RNA level in an independent cohort of 45 men with bone-metastatic CRPC and in 150 metastatic biopsies from men with mCRPC. CONCLUSIONS: Osteomimicry may contribute in part to the uptake of radium-223 within bone metastases and may thereby enhance the therapeutic benefit of this bone targeting radiotherapy.

N-Myc promotes therapeutic resistance development of neuroendocrine prostate cancer by differentially regulating miR-421/ATM pathway.

BACKGROUND: MYCN amplification or N-Myc overexpression is found in approximately 40% NEPC and up to 20% CRPC patients. N-Myc has been demonstrated to drive disease progression and hormonal therapeutic resistance of NEPC/CRPC. Here, we aim to identify the molecular mechanisms underlying the N-Myc-driven therapeutic resistance and provide new therapeutic targets for those N-Myc overexpressed NEPC/CRPC. METHODS: N-Myc overexpressing stable cell lines for LNCaP and C4-2 were generated by lentivirus infection. ADT-induced senescence was measured by SA-ß-gal staining in LNCaP cells in vitro and in LNCaP xenograft tumors in vivo. Migration, cell proliferation and colony formation assays were used to measure the cellular response after overexpressing N-Myc or perturbing the miR-421/ATM pathway. CRISPR-Cas9 was used to knock out ATM in C4-2 cells and MTS cell viability assay was used to evaluate the drug sensitivity of N-Myc overexpressing C4-2 cells in response to Enzalutamide and ATM inhibitor Ku60019 respectively or in combination. RESULTS: N-Myc overexpression suppressed ATM expression through upregulating miR-421 in LNCaP cells. This suppression alleviated the ADT-induced senescence in vitro and in vivo. Surprisingly, N-Myc overexpression upregulated ATM expression in C4-2 cells and this upregulation promoted migration and invasion of prostate cancer cells. Further, the N-Myc-induced ATM upregulation in C4-2 cells rendered the cells resistance to Enzalutamide, and inhibition of ATM by CRISPR-Cas9 knockout or ATM inhibitor Ku60019 re-sensitized them to Enzalutamide. CONCLUSIONS: N-Myc differentially regulating miR-421/ATM pathway contributes to ADT resistance and Enzalutamide resistance development respectively. Combination treatment with ATM inhibitor re-sensitizes N-Myc overexpressed CRPC cells to Enzalutamide. Our findings would offer a potential combination therapeutic strategy using ATM kinase inhibitor and Enzalutamide for the treatment of a subset of mCRPC with N-Myc overexpression that accounts for up to 20% CRPC patients.

Diabetic bladder dysfunction is associated with bladder inflammation triggered through hyperglycemia, not polyuria.

PURPOSE: Diabetes is a grave and progressive condition characterized by debilitating complications. Diabetic bladder dysfunction (DBD) is a very common complication with no specific treatments currently available. Unlike other tissues affected by this disease, the bladder is subjected to two independent insults; 1) polyuria, created by the osmotic effects of glucose in the urine, and 2) hyperglycemia itself. Based on our understanding of inflammation as a major contributor to the underlying organ damage in several other diabetic complications, its presence in the bladder during DBD and the contribution of polyuria and hyperglycemia to its development were assessed. METHODS: Awake, restrained cystometry was performed on wild type C57BL/6 mice and diabetic (Akita) mice on a C57BL/6 background at 15 weeks of age. A subgroup of the Akita mice were treated with phlorizin, an inhibitor of sodium-glucose linked transporter types 1 and 2 that prevents glucose reabsorption in the kidney. All groups were assessed for serum glucose, 4-hour voiding totals, and inflammation in the bladder (Evans blue assay). RESULTS: Akita mice develop cystometrically-defined DBD by 15 weeks of age, as evidenced by an increase in urinary frequency, a decrease in voiding volume, and an increase in post-voiding residual volume. Phlorizin effectively normalized serum glucose in these animals while increasing the urine output. Inflammation in the bladder was present in the diabetic animals at this time point, but not detectable in animals receiving phlorizin. CONCLUSION: Inflammation in the bladder of diabetic mice correlates with the development of DBD and is triggered by hyperglycemia, not polyuria.