Antigen Density Research Articles

Precision in prostate cancer detection: integrating prostate-specific antigen density (PSAD) and the Prostate Imaging Reporting and Data System (PI-RADS) to provide additional risk stratification for a more accurate diagnostic decision.

This study focuses on integrating prostate-specific antigen density (PSAD) and Prostate Imaging Reporting and Data System (PI-RADS) for enhanced risk stratification in biopsy-naïve patients. A prospective study was conducted on 339 patients with suspected prostate cancer, utilizing PSAD and PI-RADS in combination. Logistic regression models were employed, and receiver operating characteristic (ROC) analysis performed to evaluate predictive performance. The patient cohort underwent multiparametric MRI, targeted biopsy, and systematic biopsy. When patients were stratified into four PSAD risk groups, the rate of clinically significant prostate cancer (csPCa) increased significantly with higher PSAD levels. Logistic regression confirmed the independent contribution of PI-RADS and PSAD, highlighting their role in the prediction of csPCa. Combined models showed superior performance, as evidenced by the area under the curve (AUC) for PI-RADS category and PSAD (0.756), which exceeded that of the individual predictors (PSA AUC, 0.627, PI-RADS AUC 0.689, PSAD AUC 0.708). This study concludes that combining PSAD and PI-RADS improves diagnostic accuracy and predictive value for csPCa in biopsy-naïve men, resulting in a promising strategy to provide additional risk stratification for more accurate diagnostic decision in biopsy-naïve patients, especially in the PI-RADS 3 group.

Risk factors for Gleason score upgrade from prostate biopsy to radical prostatectomy.

Accurate identification of prostate cancer Gleason grade group remains an important component of the initial management of clinically localized disease. However, Gleason score upgrading (GSU) from biopsy to radical prostatectomy can occur in up to a third of patients treated with surgery. Concern for disease undergrading remains a source of diagnostic uncertainty, contributing to both over-treatment of low-risk disease as well as under-treatment of higher-risk prostate cancer. This review examines the published literature concerning risk factors for GSU from time of biopsy to prostatectomy final pathology. Risk factors identified for Gleason upgrading include patient demographic and clinical factors including age, body mass index, race, prostate volume, and biomarker based assays, including prostate-specific antigen (PSA) density, and testosterone values. In addition, prostate magnetic resonance imaging (MRI) findings have also been associated with GSU. Biopsy-specific characteristics associated with GSU include lower number of biopsy cores and lack of targeted methodology, and possibly increasing percent biopsy core positivity. Recognition of risk factors for disease undergrading may prompt confirmatory testing including repeat sampling or imaging. Continued refinements in imaging guided biopsy techniques may also reduce sampling error contributing to undergrading.

Refining clinically relevant cut-offs of prostate specific antigen density for risk stratification in patients with PI-RADS 3 lesions.

Prostate Imaging Reporting and Data System (PI-RADS) 3 lesions, identified through multiparametric magnetic resonance imaging (mpMRI), present a clinical challenge due to their equivocal nature in predicting clinically significant prostate cancer (csPCa). Aim of the study is to improve risk stratification of patients with PI-RADS 3 lesions and candidates for prostate biopsy. A cohort of 4841 consecutive patients who underwent MRI and subsequent MRI-targeted and systematic biopsies between January 2016 and April 2023 were retrospectively identified from independent prospectively maintained database. Only patients who have PI-RADS 3 lesions were included in the final analysis. A multivariable logistic regression analysis was performed to identify covariables associated with csPCa defined as International Society of Urological Pathology (ISUP) grade group ≥2. Performance of the model was evaluated using the area under the receiver operating characteristic curve (AUC), calibration, and net benefit. Significant predictors were then selected for further exploration using a Chi-squared Automatic Interaction Detection (CHAID) analysis. Overall, 790 patients had PI-RADS 3 lesions and 151 (19%) had csPCa. Significant associations were observed for age (OR: 1.1 [1.0-1.1]; p = 0.01) and PSA density (OR: 1643 [2717-41,997]; p < 0.01). The CHAID analysis identified PSAd as the sole significant factor influencing the decision tree. Cut-offs for PSAd were 0.13 ng/ml/cc (csPCa detection rate of 1% vs. 18%) for the two-nodes model and 0.09 ng/ml/cc and 0.16 ng/ml/cc for the three-nodes model (csPCa detection rate of 0.5% vs. 2% vs. 17%). For individuals with PI-RADS 3 lesions on prostate mpMRI and a PSAd below 0.13, especially below 0.09, prostate biopsy can be omitted, in order to avoid unnecessary biopsy and overdiagnosis of non-csPCa.

Advances in multiparametric magnetic resonance imaging combined with biomarkers for the diagnosis of high-grade prostate cancer.

Clinical decisions based on the test results for prostate-specific antigen often result in overdiagnosis and overtreatment. Multiparametric magnetic resonance imaging (mpMRI) can be used to identify high-grade prostate cancer (HGPCa; Gleason score ≥3 + 4); however, certain limitations remain such as inter-reader variability and false negatives. The combination of mpMRI and prostate cancer (PCa) biomarkers (prostate-specific antigen density, Proclarix, TMPRSS2:ERG gene fusion, Michigan prostate score, ExoDX prostate intelliscore, four kallikrein score, select molecular diagnosis, prostate health index, and prostate health index density) demonstrates high accuracy in the diagnosis of HGPCa, ensuring that patients avoid unnecessary prostate biopsies with a low leakage rate. This manuscript describes the characteristics and diagnostic performance of each biomarker alone and in combination with mpMRI, with the intension to provide a basis for decision-making in the diagnosis and treatment of HGPCa. Additionally, we explored the applicability of the combination protocol to the Asian population.

Preclinical studies show that Co-STARs combine the advantages of chimeric antigen and T cell receptors for the treatment of tumors with low antigen densities.

Two types of engineered T cells have been successfully used to treat patients with cancer, one with an antigen recognition domain derived from antibodies [chimeric antigen receptors (CARs)] and the other derived from T cell receptors (TCRs). CARs use high-affinity antigen-binding domains and costimulatory domains to induce T cell activation but can only react against target cells with relatively high amounts of antigen. TCRs have a much lower affinity for their antigens but can react against target cells displaying only a few antigen molecules. Here, we describe a new type of receptor, called a Co-STAR (for costimulatory synthetic TCR and antigen receptor), that combines aspects of both CARs and TCRs. In Co-STARs, the antigen-recognizing components of TCRs are replaced by high-affinity antibody fragments, and costimulation is provided by two modules that drive NF-κB signaling (MyD88 and CD40). Using a TCR-mimic antibody fragment that targets a recurrent p53 neoantigen presented in a common human leukocyte antigen (HLA) allele, we demonstrate that T cells equipped with Co-STARs can kill cancer cells bearing low densities of antigen better than T cells engineered with conventional CARs and patient-derived TCRs in vitro. In mouse models, we show that Co-STARs mediate more robust T cell expansion and more durable tumor regressions than TCRs similarly modified with MyD88 and CD40 costimulation. Our data suggest that Co-STARs may have utility for other peptide-HLA antigens in cancer and other targets where antigen density may limit the efficacy of engineered T cells.

Clinical-imaging metrics for the diagnosis of prostate cancer in PI-RADS 3 lesions

ObjectiveTo explore the feasibility and efficacy of clinical-imaging metrics in the diagnosis of prostate cancer (PCa) and clinically significant prostate cancer (csPCa) in prostate imaging-reporting and data system (PI-RADS) category 3 lesions. MethodsA retrospective analysis was conducted on lesions diagnosed as PI-RADS 3. They were categorized into benign, non-csPCa and csPCa groups. Apparent diffusion coefficient (ADC), T2-weighted imaging signal intensity (T2WISI), coefficient of variation of ADC and T2WISI, prostate-specific antigen density (PSAD), ADC density (ADCD), prostate-specific antigen lesion volume density (PSAVD) and ADC lesion volume density (ADCVD) were measured and calculated. Univariate and multivariate analyses were used to identify risk factors associated with PCa and csPCa. Receiver operating characteristic curve (ROC) and decision curves were utilized to assess the efficacy and net benefit of independent risk factors. ResultsAmong 202 patients, 133 had benign prostate disease, 25 non-csPCa and 44 csPCa. Age, PSA and lesion location showed no significant differences (P > 0.05) among the groups. T2WISI and coefficient of variation of ADC (ADCcv) were independent risk factors for PCa in PI-RADS 3 lesions, yielding an area under the curve (AUC) of 0.68. ADC was an independent risk factor for csPCa in PI-RADS 3 lesions, yielding an AUC of 0.65. Decision curve analysis showed net benefit for patients at certain probability thresholds. ConclusionsT2WISI and ADCcv, along with ADC, respectively showed considerable promise in enhancing the diagnosis of PCa and csPCa in PI-RADS 3 lesions.

Lineage-dependence of the neuroblastoma surfaceome defines tumor cell state-dependent and independent immunotherapeutic targets.

Neuroblastoma is a heterogeneous disease with adrenergic (ADRN)- and therapy resistant mesenchymal (MES)-like cells driven by distinct transcription factor networks. Here, we investigate the expression of immunotherapeutic targets in each neuroblastoma subtype and propose pan-neuroblastoma and cell state specific targetable cell-surface proteins. We characterized cell lines, patient-derived xenografts, and patient samples as ADRN-dominant or MES- dominant to define subtype-specific and pan-neuroblastoma gene sets. Targets were validated with ChIP- sequencing, immunoblotting, and flow cytometry in neuroblastoma cell lines and isogenic ADRN-to-MES transition cell line models. Finally, we evaluated the activity of MES-specific agents in vivo and in vitro . Most immunotherapeutic targets being developed for neuroblastoma showed significantly higher expression in the ADRN subtype with limited expression in MES-like tumor cells. In contrast, CD276 (B7-H3) and L1CAM maintained expression across both ADRN and MES states. We identified several receptor tyrosine kinases (RTKs) enriched in MES-dominant samples and showed that AXL targeting with ADCT-601 was potently cytotoxic in MES-dominant cell lines and showed specific anti-tumor activity in a MES cell line-derived xenograft. Immunotherapeutic strategies for neuroblastoma must address the potential of epigenetic downregulation of antigen density as a mechanism for immune evasion. We identified several RTKs as candidate MES-specific immunotherapeutic target proteins for the elimination of therapy-resistant cells. We hypothesize that the phenomena of immune escape will be less likely when targeting pan-neuroblastoma cell surface proteins such as B7-H3 and L1CAM, and/or dual targeting strategies that consider both the ADRN- and MES-cell states. Cellular plasticity influences the abundance of immunotherapeutic targets.Subtype-specific targets may be susceptible to epigenetically-mediated downregulation.Immunotherapeutic targets in development, B7-H3 and L1CAM, show "pan-subtype" expression. Neuroblastoma is a lethal childhood malignancy that shows cellular plasticity in response to anti-cancer therapies. Several plasma membrane proteins are being developed as immunotherapeutic targets in this disease. Here we define which cell surface proteins are susceptible to epigenetically regulated downregulation during an adrenergic to mesenchymal cell state switch and propose immunotherapeutic strategies to anticipate and circumvent acquired immunotherapeutic resistance.

RhIL-7-hyFc, a long-acting interleukin-7, improves efficacy of CAR-T cell therapy in solid tumors

BackgroundChimeric antigen receptor T-cell (CAR-T) therapy has achieved remarkable remission in patients with B-cell malignancies. However, its efficacy in treating solid tumors remains limited. Here, we investigated a combination therapy...

892 Prostate Specific Antigen Density (PSAD) in predicting prostate cancer: A District General Hospital Analysis

892 Prostate Specific Antigen Density (PSAD) in predicting prostate cancer: A District General Hospital Analysis

EPEN-02. CAR T-CELLS TARGETED TO B7-H3 OR HER2 FUNCTION INDEPENDENTLY OF ANTIGEN DENSITY IN XENOGRAFT MODELS OF EPENDYMOMA

Abstract BACKGROUND Targeted treatment options are desperately needed for ependymomas (EPN). Chimeric antigen receptor (CAR) T-cells have immense potential to positively transform treatment outcomes; however, little is known regarding antitumor efficacy of CAR T-cells against EPNs. Specifically, antigen density has emerged as a major influencer of CAR T-cell potency. However, the specific high and low antigen density thresholds governing CAR T-cell efficacy for EPN are unknown. We hypothesize that antigen density heterogeneity governs CAR T-cell potency against EPN. METHODS Using quantitative flow cytometry, we determined antigen density of B7-H3 and HER2 (the two CAR targets currently in pediatric EPN clinical trials) on EPN patient derived cell lines (1425, ST1, CPITT, ST2, EPI, L46SJ). We generated second generation B7-H3 and HER2-CAR T-cells with CD28z signaling domain and compared long-term cytolytic activity, expansion, and cytokine production against EPNs. RESULTS We found that all EPN cell lines express remarkably high yet variable density of B7-H3 (6.3e4 – 3.4e5 molecules/ cell). In contrast, surface density of HER2 was consistently and significantly lower (860 – 2.5e4 molecules/ cell). In repeated-stimulation assays, B7-H3-CAR T-cells killed 7-10 times and expanded up to 325,360-fold when cultured against EPN. However, we observed no significant difference in total expansion or correlation with antigen density against EPNs. Surprisingly, expansion of HER2-CAR T-cells against EPNs was drastically higher (up to over 100-billion-fold) and greatly exceeded that of B7-H3-CAR-T cells against the same EPN cells despite much lower antigen density. CONCLUSIONS Our studies reveal significant antigen density heterogeneity of B7-H3 and HER2 in EPN, which may lead to target-specific impacts on CAR T-cell persistence. Indeed, results suggest that lower antigen density of HER2 may be superior for sustained CAR T-cell activity. Future work will validate whether HER-CAR T-cells have superior antitumor efficacy in vivo to further delineate role of antigen density thresholds in CAR T-cell potency.

IMMU-02. MODIFYING CAR T CELL EPIGENETIC PROGRAMS TO IMPROVE THEIR PERSISTENCE AGAINST GROUP 3 MEDULLOBLASTOMAS

Abstract BACKGROUND Safe, effective therapies are desperately needed to improve outcomes for patients with medulloblastoma (MB), a malignant pediatric brain cancer. Chimeric antigen receptor (CAR)-T cells are a promising therapeutic option as they target T-cell cytotoxicity exclusively to tumor associated antigens. B7-homolog 3 (B7-H3) is an ideal target for CAR-T cell therapy as all MB subtypes express B7-H3 and healthy tissues do not. However, a roadblock to tumor clearance is the inability of B7-H3 CAR-T cells to persist, suggesting that improving persistence will benefit anti-tumor efficacy. The goal of this study was to compare head-to-head knocking out TET2 or DNMT3A negative epigenetic regulators of CAR-T cell persistence against group 3 MB (G3MB), the most malignant MB subtype. METHODS We generated B7-H3 CAR-T cells with CD28ζ signaling domain and performed CRISPR/Cas9 knockout (KO) of TET2, DNMT3A, and AAVS1 as a control. We compared resulting CAR-T cell persistence via repeat stimulation assays in vitro against G3MB cell lines with varying B7-H3 antigen density (D341low, HDMB03mid, and D425high). We further compared KO CAR-T cells in vivo against D341low, HDMB03mid, and D425high orthotopic xenografts. RESULTS Our data shows that DNMT3A KO, but not TET2 KO, consistently improves the persistence and expansion of CAR-T cells against G3MB in vitro. In vivo, KO of epigenetic regulators moderately improves CAR-T cell therapy against highly aggressive D341low, HDMB03mid, and D425high but is insufficient to elicit curative responses. CONCLUSIONS Our study demonstrates that genetic KO of negative epigenetic regulators of CAR-T cell persistence can improve anti-tumor function against G3MB. We conclude that for the B7-H3.CD28ζ CAR, DNMT3A KO is superior for improving persistence over TET2 KO, but that DNMT3A KO is insufficient in vivo. We believe this is due to the aggressive nature of G3MB and we are optimizing in vivo studies for better representation of CAR-T cell persistence.

Analysis of polyfunctionality for enhanced BAFF-R CAR T-cell therapy for hematologic malignancies

AbstractChimeric antigen receptor (CAR) T-cell therapy has emerged as a promising immunotherapeutic strategy for eradicating human cancers. Their therapeutic success and durability of clinical responses hinges, in large part, on their functional capacity, including the ability of these engineered cells to simultaneously expand and persist after infusion into patients. CD19 CAR T-cell polyfunctionality, assessing the simultaneous functions of cytokine production, proliferation, and cytotoxicity has been reported to correlate with clinical outcomes. Assay optimization is potentially limited by the heterogeneous nature of CAR T-cell infusion products and target specificity. We optimized a single-cell platform for polyfunctionality using CAR T-cell products manufactured from healthy donors, engineered against a novel target, B-cell–activating factor receptor (BAFF-R) and validated the protocol using CD19 CAR T cells. We observed distinct qualitative differences between BAFF-R and CD19 CAR T cells relative to the proportions of stimulatory vs effector cytokines, based on target antigen density, and, generally, CD19 CAR T cells exhibited lower indices of polyfunctionality. Finally, we applied our assay to the autologous BAFF-R CAR T-cell product generated from the first patient with non-Hodgkin lymphoma treated in an ongoing clinical trial who had progressed after prior CD19 CAR T-cell therapy. We observed robust indicators of polyfunctionality, which correlated with successful CAR T-cell expansion after infusion and achievement of durable complete remission ongoing after 18 months. The precise identification of factors determining the role of BAFF-R CAR T-cell fitness in toxicity and clinical outcome will require the application of this robust assay in the analysis of additional treated patients. This trial was registered at www.ClinicalTrials.gov as #NCT05370430.

Outcomes of active surveillance for Japanese patients with prostate cancer (PRIAS-JAPAN).

To report the outcomes of repeat biopsies, metastasis and survival in the Prostate Cancer Research International: Active Surveillance (PRIAS)-JAPAN study, a prospective observational study for Japanese patients, initiated in 2010. At the beginning,inclusion criteria were initially low-risk patients, prostate-specific antigen (PSA) density (PSAD) <0.2, and ≤2 positive biopsy cores. As from 2014, GS3+4 has also been allowed for patients aged 70 years and over. Since January 2021, the age limit for Gleason score (GS) 3 + 4 cases was removed, and eligibility criteria were expanded to PSA ≤20 ng/mL, PSAD <0.25 nd/mL/cc, unlimited number of positive GS 3 + 3 cores, and positive results for fewer than half of the total number of cores for GS 3 + 4 cases if magnetic resonance imaging fusion biopsy was performed at study enrolment or subsequent follow-up. For patients eligible for active surveillance, PSA tests were performed every 3 months, rectal examination every 6 months, and biopsies at 1, 4, 7 and 10 years, followed by every 5 years thereafter. Patients with confirmed pathological reclassification were recommended for secondary treatments. As of February 2024, 1302 patients were enrolled in AS; 1274 (98%) met the eligibility criteria. The median (interquartile range) age, PSA level, PSAD, and number of positive cores were 69 (64-73) years, 5.3 (4.5-6.6) ng/mL, 0.15 (0.12-0.17) ng/mL, and 1 (1-2), respectively. The clinical stage was T1c in 1089 patients (86%) and T2 in 185 (15%). The rates of acceptance by patients for the first, second, third and fourth re-biopsies were 83%, 64%, 41% and 22%, respectively. The pathological reclassification rates for the first, second, third and fourth re-biopsies were 29%, 30%, 35% and 25%, respectively. The 1-, 5- and 10-year persistence rates were 77%, 45% and 23%, respectively. Six patients developed metastasis, and one patient died from prostate cancer. Pathological reclassification was observed in approximately 30% of the patients during biopsy; however, biopsy acceptance rates decreased over time. Although metastasis occurred in six patients, only one death from prostate cancer was recorded.

Prostate cancer detection rate with MRI-targeted biopsy alone using outpatient transperineal prostate biopsy.

We aimed to compare the detection rate of prostate cancer (PCa) and clinically significant (cs) PCa by magnetic resonance imaging-guided targeted biopsy (MTBx) alone and MTBx plus systematic biopsy (SBx) using an outpatient transperineal (TP) approach under local anesthesia. A retrospective study of patients who underwent outpatient TP prostate biopsy under local anesthesia at our tertiary institution between 2019 and 2022 was performed. To compare the proportions of PCa and csPCa in both pathways, McNemar's tests were used. Multivariable logistic regression model was fitted to determine the predictors of csPCa. Of 255 men included, 177 (69%) underwent MTBx alone. MTBx had similar detection rate for PCa (56%) and csPCa (47%) compared to the combination of MTBx and SBx (PCa 61%; csPCa 49%; p=0.1 and p=0.3, respectively). MTBx had lower median number of biopsy cores compared to the combination of MTBx and SBx (6 vs. 11, p<0.001). At multivariable logistic regression analysis, age (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.04-1.13, p<0.001), prior negative biopsy (OR 0.19, 95% CI 0.09-0.44, p<0.001), prostate-specific antigen density cutoff ≥0.15 (OR 3.17, 95% CI 1.67-6.01, p<0.001), and prostate imaging reporting and data system ≥4 (OR 12.2, 95% CI 4.21-35.6, p<0.001) were independent predictors of csPCa. MTBx showed similar diagnostic performance to the combination of MTBx and SBx in patients undergoing outpatient TP prostate biopsy. Future studies are needed to evaluate the role of MTBx in avoiding unnecessary biopsies.

Prostate cancer with elevated free prostate-specific antigen density: A case report

BACKGROUND Prostate cancer is the second most common cancer among men worldwide, and prostate-specific antigen (PSA) is often used in clinical practice to screen for prostate cancer. Normal total PSA (tPSA) level initially excludes prostate cancer. Here, we report a case of prostate cancer with elevated free PSA density (fPSAD). CASE SUMMARY A patient diagnosed with benign prostatic hyperplasia underwent prostatectomy, and the postoperative pathological results showed acinar adenocarcinoma of the prostate. The patient is currently undergoing endocrine chemotherapy. CONCLUSION We provide a clinical reference for diagnosis and treatment of patients with normal tPSA but elevated fPSAD.

IgG and IgM differentiation in a particle-based agglutination assay by control over antigen surface density.

Point-of-care (POC) testing offers fast and on-site diagnostics and can be crucial against many infectious diseases and in screening. One remaining challenge in serological POC testing is the quantification of immunoglobulin G (IgG) and immunoglobulin M (IgM). Quantification of IgG/IgM can be important to evaluate immunity and to discriminate recent infections from past infections and primary infections from secondary infections. POC tests such as lateral flow immunoassays allow IgG and IgM differentiation; however, a remaining limitation is their incapacity to provide quantitative results. In this work, we show how samples containing IgG or IgM can be distinguished in a nanoparticle-based agglutination biosensing assay by tuning the density of antigens on the nanoparticles' surface. We employ direct STochastic Optical Reconstruction Microscopy to quantify the accessible SARS-CoV-2 trimeric spike proteins conjugated to magnetic nanoparticles at a single-particle level and gain insight into the protein distribution provided by the conjugation procedure. Furthermore, we measure the anti-SARS-CoV-2 IgG/IgM induced agglutination using an optomagnetic readout principle. We show that particles with high antigen density have a relatively higher sensitivity toward IgM compared to IgG, whereas low antigen density provides a relatively higher sensitivity to IgG. The finding paves the way for its implementation for other agglutination-based serology tests, allowing for more accurate disease diagnosis.

Risk factor analysis and optimal cutoff value selection of PSAD for diagnosing clinically significant prostate cancer in patients with negative mpMRI: results from a high-volume center in Southeast China

BackgroundMulti-parametric magnetic resonance imaging (mpMRI) is a diagnostic tool used for screening, localizing, and staging prostate cancer. Patients with Prostate Imaging Reporting and Data System (PI-RADS) score of 1 and 2 are considered negative mpMRI, with a lower likelihood of detecting clinically significant prostate cancer (csPCa). However, relying solely on mpMRI is insufficient to completely exclude csPCa, necessitating further stratification of csPCa patients using biomarkers.MethodsA retrospective study was conducted on mpMRI-negative patients who underwent prostate biopsy at the First Affiliated Hospital of Zhejiang University from January 2022 to June 2023. A total of 607 patients were included based on inclusion and exclusion criteria. Univariate and multivariate logistic regression analysis were performed to identify risk factors for diagnosing csPCa in patients with negative mpMRI. Receiver Operating Characteristic (ROC) curves were plotted to compare the discriminatory ability of different Prostate-Specific Antigen Density (PSAD) cutoff values for csPCa.ResultsAmong the 607 patients with negative mpMRI, 73 patients were diagnosed with csPCa. In univariate logistic regression analysis, age, PSA, f/tPSA, prostate volume, and PSAD were all associated with diagnosing csPCa in patients with negative mpMRI (P < 0.05), with PSAD being the most accurate predictor. In multivariate logistic regression analysis, f/tPSA, age, and PSAD were independent predictors of csPCa (P < 0.05). PSAD cutoff value of 0.20 ng/ml/ml has better discriminatory ability for predicting csPCa and is a significant risk factor for csPCa in multivariate analysis.ConclusionAge, f/tPSA, and PSAD are independent predictors of diagnosing csPCa in patients with negative mpMRI. It is suggested that patients with negative mpMRI and PSAD less than 0.20 ng/ml/ml could avoid prostate biopsy, as a PSAD cutoff value of 0.20 ng/ml/ml has better diagnostic performance than the traditional cutoff value of 0.15 ng/ml/ml.

Unraveling resistance mechanisms in anti-CD19 chimeric antigen receptor-T therapy for B-ALL: a novel in vitro model and insights into target antigen dynamics

BackgroundCellular immunotherapy, represented by the chimeric antigen receptor T cell (CAR-T), has exhibited high response rates, durable remission, and safety in vitro and in clinical trials. Unfortunately, anti-CD19 CAR-T (CART-19) treatment alone is prone to relapse and has a particularly poor prognosis in relapsed/refractory (r/r) B-ALL patients. To date, addressing or reducing relapse remains one of the research priorities to achieve broad clinical application.MethodsWe manufactured second generation CART-19 cells and validated their efficacy and safety in vitro and in vivo. Through co-culture of Nalm-6 cells with short-term cultured CART-19 cells, CD19-negative Nalm-6 cells were detected by flow cytometry, and further investigation of the relapsed cells and their resistance mechanisms was evaluated in vitro.ResultsIn this study, we demonstrated that CART-19 cells had enhanced and specific antileukemic activities, and the survival of B-ALL mouse models after CART-19 treatment was significantly prolonged. We then shortened the culture time and applied the serum-free culture to expand CAR-T cells, followed by co-culturing CART-19 cells with Nalm-6 cells. Surprisingly, we observed the proliferation of CD19-negative Nalm-6 cells around 28 days. Identification of potential resistance mechanisms showed that the relapsed cells express truncated CD19 proteins with decreased levels and, more importantly, CAR expression was detected on the relapsed cell surface, which may ultimately keep them antigen-negative. Furthermore, it was validated that CART-22 and tandem CART-22/19 cells could effectively kill the relapsed cells, but neither could completely eradicate them.ConclusionsWe successfully generated CART-19 cells and obtained a CD19-negative refractory relapsed B-ALL cell line, providing new insights into the underlying mechanisms of resistance and a new in vitro model for the treatment of r/r B-ALL patients with low antigen density.

A novel model incorporating quantitative contrast-enhanced ultrasound into PI-RADSv2-based nomogram detecting clinically significant prostate cancer

The diagnostic accuracy of clinically significant prostate cancer (csPCa) of Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) is limited by subjectivity in result interpretation and the false positive results from certain similar anatomic structures. We aimed to establish a new model combining quantitative contrast-enhanced ultrasound, PI-RADSv2, clinical parameters to optimize the PI-RADSv2-based model. The analysis was conducted based on a data set of 151 patients from 2019 to 2022, multiple regression analysis showed that prostate specific antigen density, age, PI-RADSv2, quantitative parameters (rush time, wash-out area under the curve) were independent predictors. Based on these predictors, we established a new predictive model, the AUCs of the model were 0.910 and 0.879 in training and validation cohort, which were higher than those of PI-RADSv2-based model (0.865 and 0.821 in training and validation cohort). Net Reclassification Index analysis indicated that the new predictive model improved the classification of patients. Decision curve analysis showed that in most risk probabilities, the new predictive model improved the clinical utility of PI-RADSv2-based model. Generally, this new predictive model showed that quantitative parameters from contrast enhanced ultrasound could help to improve the diagnostic performance of PI-RADSv2 based model in detecting csPCa.

The impact of prostate volume estimation on the risk-adapted biopsy decision based on prostate-specific antigen density and magnetic resonance imaging score.

Utility of prostate-specific antigen density (PSAd) for risk-stratification to avoid unnecessary biopsy remains unclear due to the lack of standardization of prostate volume estimation. We evaluated the impact of ellipsoidal formula using multiparametric magnetic resonance (MRI) and semi-automated segmentation using tridimensional ultrasound (3D-US) on prostate volume and PSAd estimations as well as the distribution of patients in a risk-adapted table of clinically significant prostate cancer (csPCa). In a prospectively maintained database of 4841 patients who underwent MRI-targeted and systematic biopsies, 971 met inclusions criteria. Correlation of volume estimation was assessed by Kendall's correlation coefficient and graphically represented by scatter and Bland-Altman plots. Distribution of csPCa was presented using the Schoots risk-adapted table based on PSAd and PI-RADS score. The model was evaluated using discrimination, calibration plots and decision curve analysis (DCA). Median prostate volume estimation using 3D-US was higher compared to MRI (49cc[IQR 37-68] vs 47cc[IQR 35-66], p < 0.001). Significant correlation between imaging modalities was observed (τ = 0.73[CI 0.7-0.75], p < 0.001). Bland-Altman plot emphasizes the differences in prostate volume estimation. Using the Schoots risk-adapted table, a high risk of csPCa was observed in PI-RADS 2 combined with high PSAd, and in all PI-RADS 4-5. The risk of csPCa was proportional to the PSAd for PI-RADS 3 patients. Good accuracy (AUC of 0.69 and 0.68 using 3D-US and MRI, respectively), adequate calibration and a higher net benefit when using 3D-US for probability thresholds above 25% on DCA. Prostate volume estimation with semi-automated segmentation using 3D-US should be preferred to the ellipsoidal formula (MRI) when evaluating PSAd and the risk of csPCa.