Platelet-Coated Circulating Tumor Cells Are a Predictive Biomarker in Patients with Metastatic Castrate-Resistant Prostate Cancer

Longitudinal tracking of circulating rare events in the liquid biopsy of stage III-IV non-small cell lung cancer patients

In the United States, lung cancer is the second most common type of cancer with non-small cell lung cancer (NSCLC) encompassing around 85% of total lung cancer cases. Late-stage patients with metastatic disease have worsening prognosis, highlighting the importance of longitudinal disease monitoring. Liquid biopsy (LBx) represents a way for physicians to non-invasively track tumor analytes, such as circulating tumor cells (CTCs), and understand tumor progression in real-time through analyzing longitudinal blood samples. CTCs have been shown to be effective predictive biomarkers in measuring treatment efficacy and survival outcomes. We used the third-generation High-Definition Single Cell Assay (HDSCA3.0) workflow to analyze circulating rare events longitudinally during treatment in a cohort of 10 late-stage NSCLC patients, identifying rare events including circulating cancer cells (i.e., CTCs), and oncosomes. Here, we show (1) that there is a cancer specific LBx profile, (2) there is considerable heterogeneity of rare cells and oncosomes, and (3) that LBx data elements correlated with patient survival outcomes. Additional studies are warranted to understand the biological significance of the rare events detected, and the clinical potential of the LBx to monitor and predict response to treatment in NSCLC patient care.

Blood-based liquid biopsy: A promising noninvasive test in diagnosis, surveillance, and prognosis of patients with upper tract urothelial carcinoma

OBJECTIVES

To assess the efficacy of blood-based liquid biopsy in the diagnosis, surveillance, and prognosis of upper tract urothelial carcinoma (UTUC).

METHODS AND MATERIALS

In this prospective study, peripheral blood samples were collected from patients with primary UTUC before surgery with curative intent and follow-up visits at University of Southern California between May 2021 and September 2022. The samples were analyzed using the third-generation comprehensive high-definition single-cell assay (HDSCA3.0) to detect rare events, including circulating tumor cells (CTCs) and oncosomes, based on the immunofluorescence signals of DAPI (D), cytokeratin (CK), CD45/CD31 (CD), and vimentin (V). The findings of pre-surgery liquid biopsies were compared with those of blood samples from normal donors (NDs) and matched follow-up liquid biopsies. The association between liquid biopsy findings and clinical data, including recurrence-free survival (RFS), was also assessed.

RESULTS

Twenty-eight patients with UTUC were included, of whom 21 had follow-up samples. Significant differences in specific rare analytes were detected in the preoperative samples compared to the NDs. In the post- vs. presurgery matched analysis, a significant decrease was detected in total-, CK-, and CK|V oncosomes, as well as in D-, D|V-, and D|V|CD cells. With a median follow-up of 11 months, 8 patients had disease recurrence. Survival analysis demonstrated that patients with >1.95 preoperative CK|V oncosomes (p = 0.020) and those with >4.18 D|CK|V cells (p = 0.050) had worse RFS compared to other patients.

CONCLUSIONS

This study demonstrated promising initial evidence for the biomarker role of CTCs and oncosomes in the diagnosis and surveillance of patients with UTUC.

Liquid biopsy approach to monitor the efficacy and response to CAR-T cell therapy

BACKGROUND

Chimeric antigen receptor (CAR)-T cells are approved for use in the treatment of hematological malignancies. Axicabtagene ciloleucel (YESCARTA) and brexucabtagene autoleucel (TECARTUS) genetically modified autologous T cells expressing an anti-CD19 scFv based on the FMC63 clone have shown impressive response rates for the treatment of CD19+B cell malignancies, but there remain challenges in monitoring long-term persistence as well as the functional characterization of low-level persisting CAR-T cells in patients. Furthermore, due to CD19-negative driven relapse, having the capability to monitor patients with simultaneous detection of the B cell malignancy and persisting CAR-T cells in patient peripheral blood is important for ensuring timely treatment optionality and understanding relapse.

METHODS

This study demonstrates the development and technical validation of a comprehensive liquid biopsy, high-definition single cell assay (HDSCA)-HemeCAR for (1) KTE-X19 CAR-T cell identification and analysis and (2) simultaneously monitoring the CD19-epitope landscape on neoplastic B cells in cryopreserved or fresh peripheral blood. Proprietary anti-CD19 CAR reagents, healthy donor transduced CAR-T cells, and patient samples consisting of malignant B cell fractions from manufacturing were used for assay development.

RESULTS

The CAR-T assay showed an approximate limit of detection at 1 cell in 3 million with a sensitivity of 91%. Genomic analysis was additionally used to confirm the presence of the CAR transgene. This study additionally reports the successful completion of two B cell assays with multiple CD19 variants (FMC63 and LE-CD19) and a unique fourth channel biomarker (CD20 or CD22). In patient samples, we observed that CD19 isoforms were highly heterogeneous both intrapatient and interpatient.

CONCLUSIONS

With the simultaneous detection of the CAR-T cells and the B cell malignancy in patient peripheral blood, the HDSCA-HemeCAR workflow may be considered for risk monitoring and patient management.

Concordance and Clinical Significance of Genomic Alterations in Progressive Tumor Tissue and Matched Circulating Tumor DNA in Aggressive-variant Prostate Cancer

Sequencing of circulating tumor DNA (ctDNA) is a minimally invasive approach to reveal the genomic alterations of cancer; however, its comparison with sequencing of tumor tissue has not been well documented in real-world patients with aggressive-variant prostate cancer (AVPC). Concordance of genomic alterations was assessed between progressive tumor tissue and matched ctDNA by next-generation sequencing for 63 patients with AVPC. Associations of genomic alterations with progression-free survival (PFS) and overall survival (OS) were investigated using Kaplan-Meier and Cox regression analyses. A total of 161 somatic mutations (SMs) and 84 copy-number variants (CNVs) were detected in tumors, of which 97 were also found in ctDNA, giving concordance of 39.6% (97/245) across all SMs and CNVs, 49.7% for SMs only and 20.2% for CNVs only. Across all patients with AVPC, chemotherapy was associated with significantly longer median PFS (6 vs. 0.75 months, P = 0.001) and OS (11 vs. 8 months, P < 0.001) than next-generation hormonal therapy (NHT). Among types of chemotherapy, additional platinum-based chemotherapy was associated with significantly longer median PFS and OS than docetaxel only in patients with TP53, RB1, or PTEN alterations, and in those with ctDNA% ≥ 13.5%. The concordance analysis first provides evidence for combining the sequencing of ctDNA and tumor tissue in real-world patients with AVPC. Chemotherapy is associated with significantly better survival than NHT, and the benefit of additional platinum-based chemotherapy may depend on the presence of alterations in TP53, RB1, or PTEN and on a sufficiently high proportion of ctDNA in patients with AVPC.

SIGNIFICANCE

AVPC is a highly malignant and heterogeneous disease. Sequencing of ctDNA is a minimally invasive approach to reveal genomic alterations. On the basis of the current real-world study, we found ctDNA does not fully recapitulate the landscape of genomic alterations from progressive tumor tissue in AVPC. We also revealed AVPC can benefit from chemotherapy, especially platinum-based regimens. TP53/RB1/PTEN alterations in ctDNA or tumor tissue could be biomarkers for platinum-based chemotherapy in this setting.

Targeted single-cell proteomic analysis identifies new liquid biopsy biomarkers associated with multiple myeloma

Multiple myeloma (MM) is accompanied by alterations to the normal plasma cell (PC) proteome, leading to changes to the tumor microenvironment and disease progression. There is a great need for understanding the consequences that lead to MM progression and for the discovery of new biomarkers that can aid clinical diagnostics and serve as targets for therapeutics. This study demonstrates the applicability of utilizing the single-cell high-definition liquid biopsy assay (HDSCA) and imaging mass cytometry to characterize the proteomic profile of myeloma. In our study, we analyzed ~87,000 cells from seven patient samples (bone marrow and peripheral blood) across the myeloma disease spectrum and utilized our multiplexed panel to characterize the expression of clinical markers for PC classification, additional potential therapeutic targets, and the tumor microenvironment cells. Our analysis showed BCMA, ICAM3 (CD50), CD221, and CS1 (SLAMF7) as the most abundantly expressed markers on PCs across all myeloma stages, with BCMA, ICAM3, and CD221 having significantly higher expression levels on disease versus precursor PCs. Additionally, we identify significantly elevated levels of expression for CD74, MUM1, CD229, CD44, IGLL5, Cyclin D1, UBA52, and CD317 on PCs from overt disease conditions compared to those from precursor states.

Cell State and Cell Type: Deconvoluting Circulating Tumor Cell Populations in Liquid Biopsies by Multi-Omics

Bi-directional crosstalk between the tumor and the tumor microenvironment (TME) has been shown to increase the rate of tumor evolution and to play a key role in neoplastic progression, therapeutic resistance, and a patient's overall survival. Here, we set out to use a comprehensive liquid-biopsy analysis to study cancer and specific TME cells in circulation and their association with disease status. Cytokeratin+, CD45- circulating rare cells (CRCs) from nine breast and four prostate cancer patients were characterized through morphometrics, single-cell copy number analysis, and targeted multiplexed proteomics to delineate cancer cell lineage from other rare cells originating in the TME. We show that we can detect epithelial circulating tumor cells (EPI.CTC), CTCs undergoing epithelial-to-mesenchymal transition (EMT.CTC) and circulating endothelial cells (CECs) using a universal rare event detection platform (HDSCA). Longitudinal analysis of an index patient finds that CTCs are present at the time of disease progression, while CECs are predominately present at the time of stable disease. In a small cohort of prostate and breast cancer patients, we find high inter-patient and temporal intra-patient variability in the expression of tissue specific markers such as ER, HER2, AR, PSA and PSMA and EpCAM. Our study stresses the importance of the multi-omic characterization of circulating rare cells in patients with breast and prostate carcinomas, specifically highlighting overlapping and cell type defining proteo-genomic characteristics of CTCs and CECs.

Plasticity of circulating tumor cells in small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumor with low five-year survival rates. Recently described molecular phenotypes of SCLC exhibit differential vulnerabilities heralding potential for stratified treatment. Whilst tumor biopsy in SCLC is challenging, circulating tumor cells in the liquid biopsy are prevalent and can be repeatedly sampled accommodating the dynamic plasticity of SCLC phenotypes. The aim of this study was to characterize the heterogeneity of rare circulating cells with confirmed tumor origin and to explore a liquid biopsy approach for future clinical trials of targeted therapies. This study applied the 3rd generation of a previously validated direct imaging platform to 14 chemo-naive SCLC patients and 10 non-cancerous normal donor (ND) samples. Phenotypic heterogeneity of circulating rare cells in SCLC was observed and a patient-level classification model was established to stratify SCLC patients from non-cancerous donors. Eight rare cell groups, with combinations of epithelial, endothelial, and mesenchymal biomarker expression patterns, were phenotypically characterized. The single-cell genomic analysis confirmed the cancer cell plasticity in every rare cell group harboring clonal genomic alterations. This study shows rare cell heterogeneity and confirms cellular plasticity in SCLC providing a valuable resource for better opportunities to discover novel therapeutic targets in SCLC.

Recent Advances in Blood-Based Liquid Biopsy Approaches in Prostate Cancer

ABSTRACT

The advent of high-throughput technologies has enabled the analysis of minute amounts of tumor-derived material purified from body fluids, termed "liquid biopsies." Prostate cancer (PCa) management, like in many other cancer types, has benefited from liquid biopsies at several stages of the disease. Although initially describing circulating tumor cells in blood, the term "liquid biopsy" has come to more prominently include cell-free, circulating tumor DNA, as well as RNA, proteins, and other molecules. They provide tumor molecular information representing the entire, often-heterogeneous disease, relatively noninvasively and longitudinally. Blood has been the main liquid biopsy specimen in PCa, and urine has also proven beneficial. Technological advances have allowed clinical implementation of some liquid biopsies in PCa, in disease monitoring and precision oncology. This narrative review introduces the main types of blood-based PCa liquid biopsies focusing on advances in the past 5 years. Clinical adoption of liquid biopsies to detect and monitor the evolving PCa tumor biology promises to deepen our understanding of the disease and improve patient outcomes.

Association between the Immunophenotype of Peripheral Blood from mCRPC Patients and the Outcomes of Radium-223 Treatment

(1) Background: Prostate cancer is the second most common cancer in men, with androgen suppression as the standard treatment. Despite initially responding to castration, most metastatic prostate cancer patients eventually experience progression. In these cases, Radium-223 is the chosen treatment. We hypothesized that the immunophenotype of circulating leukocytes conditions the response to Radium-223 treatment. (2) Material and Methods: In this prospective study, we collected peripheral blood from twelve mCRPC patients and nine healthy donors before (baseline) and during treatment with Radium-223. Immunophenotyping and the percentages of leukocyte-platelet complexes were determined by flow cytometry. The increments or decrements of leukocyte subsets between the baseline and the second Radium-223 injection were also calculated. (3) Results: At baseline, the mCRPC patients had a lower percentages of CD4⁺ T cells and B cells and higher percentages of NK and neutrophils than the HDs. In addition, they had more OX40⁺ CD4⁺ T cells, PD-L1⁺ CD8^low cells, PD-L1⁺ B cells, PD-L1⁺ NK cells, and monocyte-platelet complexes than the HDs. Moreover, patients with slow and fast progression had different percentages of PD-L1⁺ CD8⁺ T cells. In particular, slow progression patients underwent an increment of PD-L1⁺ CD8⁺ T cells after two cycles of Radium-223. (4) Conclusions: The characterization of circulating immune cells before initiating Radium-223 treatment could become a non-invasive indicator of the response.

Investigation of liquid biopsy analytes in peripheral blood of individuals after SARS-CoV-2 infection

BACKGROUND

Post-acute COVID-19 syndrome (PACS) is linked to severe organ damage. The identification and stratification of at-risk SARS-CoV-2 infected individuals is vital to providing appropriate care. This exploratory study looks for a potential liquid biopsy signal for PACS using both manual and machine learning approaches.

METHODS

Using a high definition single cell assay (HDSCA) workflow for liquid biopsy, we analysed 100 Post-COVID patients and 19 pre-pandemic normal donor (ND) controls. Within our patient cohort, 73 had received at least 1 dose of vaccination prior to SARS-CoV-2 infection. We stratified the COVID patients into 25 asymptomatic, 22 symptomatic COVID-19 but not suspected for PACS and 53 PACS suspected. All COVID-19 patients investigated in this study were diagnosed between April 2020 and January 2022 with a median 243 days (range 16-669) from diagnosis to their blood draw. We did a histopathological examination of rare events in the peripheral blood and used a machine learning model to evaluate predictors of PACS.

FINDINGS

The manual classification found rare cellular and acellular events consistent with features of endothelial cells and platelet structures in the PACS-suspected cohort. The three categories encompassing the hypothesised events were observed at a significantly higher incidence in the PACS-suspected cohort compared to the ND (p-value < 0.05). The machine learning classifier performed well when separating the NDs from Post-COVID with an accuracy of 90.1%, but poorly when separating the patients suspected and not suspected of PACS with an accuracy of 58.7%.

INTERPRETATION

Both the manual and the machine learning model found differences in the Post-COVID cohort and the NDs, suggesting the existence of a liquid biopsy signal after active SARS-CoV-2 infection. More research is needed to stratify PACS and its subsyndromes.

FUNDING

This work was funded in whole or in part by Fulgent Genetics, Kathy and Richard Leventhal and Vassiliadis Research Fund. This work was also supported by the National Cancer InstituteU54CA260591.

High Platelet Count is a Potential Prognostic Factor of the Early Recurrence of Hepatocellular Carcinoma in the Presence of Circulating Tumor Cells

Purpose

Recent studies indicated the vital role of platelet in enhancing the survival of circulating tumor cells (CTCs) in the blood, thereby stimulating the metastasis of tumors. CTCs have been considered an indicator of early tumor recurrence. Therefore, this study evaluated the prognostic potential of platelet count in predicting the early recurrence of hepatocellular carcinoma (HCC) in the presence of CTCs.

Patients and Methods

127 patients, whose preoperative CTCs were detected, were enrolled in this study. Univariate analysis was performed to identify the significant association of factors with the early recurrence of HCC, followed by multivariate analysis to determine the independent prognostic indicators. The prediction potential was evaluated using receiver operating characteristic (ROC) curves.

Results

A total of 81 (63.7%) patients showed early HCC recurrence. The platelet count ≥225×10⁹/L (hazard ratio, HR: 1.679, P = 0.041), CTCs >5/5 mL (HR: 2.467, P = 0.001), and presence of microvascular invasion (MVI) (HR: 2.580, P = 0.002) were independent factors correlated with the early recurrence of HCC in multivariate analysis. The prognostic potential of the combined CTCs-platelet count (0.738) was better than that of CTCs (0.703) and platelet (0.604) alone. The subgroup analysis, excluding 23 patients with pathological cirrhosis and splenomegaly, showed that the platelet count ≥225×10⁹/L and CTCs >5/5 mL were also independent factors of early HCC recurrence. The prediction potential of the combined CTCs-platelet count was 0.753, which was better than that of the whole cohort. Kaplan-Meier survival curve analysis indicated that the HCC patients with high platelet or CTCs had the worse recurrence-free survival (RFS).

Conclusion

The high platelet count was an independent factor of early HCC recurrence in the presence of CTCs. The combination of preoperative CTCs and platelet count could effectively predict the early recurrence of HCC. The subgroup analysis also showed similar results.

Characterization of BCMA Expression in Circulating Rare Single Cells of Patients with Plasma Cell Neoplasms

B-cell maturation antigen (BCMA), a key regulator of B-cell proliferation and survival, is highly expressed in almost all cases of plasma cell neoplasms and B-lymphoproliferative malignancies. BCMA is a robust biomarker of plasma cells and a therapeutic target with substantial clinical significance. However, the expression of BCMA in circulating tumor cells of patients with hematological malignancies has not been validated for the detection of circulating plasma and B cells. The application of BCMA as a biomarker in single-cell detection and profiling of circulating tumor cells in patients' blood could enable early disease profiling and therapy response monitoring. Here, we report the development and validation of a slide-based immunofluorescence assay (i.e., CD138, BCMA, CD45, DAPI) for enrichment-free detection, quantification, and morphogenomic characterization of BCMA-expressing cells in patients (N = 9) with plasma cell neoplasms. Varying morphological subtypes of circulating BCMA-expressing cells were detected across the CD138(+/-) and CD45(+/-) compartments, representing candidate clonotypic post-germinal center B cells, plasmablasts, and both normal and malignant plasma cells. Genomic analysis by single-cell sequencing and correlation to clinical FISH cytogenetics provides validation, with data showing that patients across the different neoplastic states carry both normal and altered BCMA-expressing cells. Furthermore, altered cells harbor cytogenetic events detected by clinical FISH. The reported enrichment-free liquid biopsy approach has potential applications as a single-cell methodology for the early detection of BCMA+ B-lymphoid malignancies and in monitoring therapy response for patients undergoing anti-BCMA treatments.

Defining A Liquid Biopsy Profile of Circulating Tumor Cells and Oncosomes in Metastatic Colorectal Cancer for Clinical Utility

Simple Summary

Metastatic colorectal cancer (mCRC) is typified by its tumor heterogeneity and changing disease states, suggesting that personalized medicine approaches could be vital to improving clinical practice. As a minimally invasive approach, the liquid biopsy has the potential to be a powerful longitudinal prognostic tool. We investigated mCRC patients’ peripheral blood samples using an enrichment-free single-cell approach to capture the broader rare-event population beyond the conventionally detected epithelial-derived circulating tumor cell (CTC). Our analysis reveals a heterogenous profile of CTCs and oncosomes not commonly found in normal donor samples. We identified select rare cell types based on their distinct immunofluorescence expression and morphology across multiple assays. Lastly, we highlight correlations between enumerations of the blood-based analytes and progression-free survival. This study clinically validates an unbiased rare-event approach in the liquid biopsy, motivating future studies to further investigate these analytes for their prognostic potential.

Abstract

Metastatic colorectal cancer (mCRC) is characterized by its extensive disease heterogeneity, suggesting that individualized analysis could be vital to improving patient outcomes. As a minimally invasive approach, the liquid biopsy has the potential to longitudinally monitor heterogeneous analytes. Current platforms primarily utilize enrichment-based approaches for epithelial-derived circulating tumor cells (CTC), but this subtype is infrequent in the peripheral blood (PB) of mCRC patients, leading to the liquid biopsy’s relative disuse in this cancer type. In this study, we evaluated 18 PB samples from 10 mCRC patients using the unbiased high-definition single-cell assay (HDSCA). We first employed a rare-event (Landscape) immunofluorescence (IF) protocol, which captured a heterogenous CTC and oncosome population, the likes of which was not observed across 50 normal donor (ND) samples. Subsequent analysis was conducted using a colorectal-targeted IF protocol to assess the frequency of CDX2-expressing CTCs and oncosomes. A multi-assay clustering analysis isolated morphologically distinct subtypes across the two IF stains, demonstrating the value of applying an unbiased single-cell approach to multiple assays in tandem. Rare-event enumerations at a single timepoint and the variation of these events over time correlated with progression-free survival. This study supports the clinical utility of an unbiased approach to interrogating the liquid biopsy in mCRC, representing the heterogeneity within the CTC classification and warranting the further molecular characterization of the rare-event analytes with clinical promise.

Multianalyte liquid biopsy to aid the diagnostic workup of breast cancer

Breast cancer (BC) affects 1 in every 8 women in the United States and is currently the most prevalent cancer worldwide. Precise staging at diagnosis and prognosis are essential components for the clinical management of BC patients. In this study, we set out to evaluate the feasibility of the high-definition single cell (HDSCA) liquid biopsy (LBx) platform to stratify late-stage BC, early-stage BC, and normal donors using peripheral blood samples. Utilizing 5 biomarkers, we identified rare circulating events with epithelial, mesenchymal, endothelial and hematological origin. We detected a higher level of CTCs in late-stage patients, compared to the early-stage and normal donors. Additionally, we observed more tumor-associated large extracellular vesicles (LEVs) in the early-stage, compared to late-stage and the normal donor groups. Overall, we were able to detect reproducible patterns in the enumeration of rare cells and LEVs of cancer vs. normal donors and early-stage vs. late-stage BC with high accuracy, allowing for robust stratification. Our findings illustrate the feasibility of the LBx assay to provide robust detection of rare circulating events in peripheral blood draws and to stratify late-stage BC, early-stage BC, and normal donor samples.

Cell-Cell Interactions Drive Metastasis of Circulating Tumor Microemboli

Circulating tumor cells are the cellular mediators of distant metastasis in solid malignancies. Their metastatic potential can be augmented by clustering with other tumor cells or nonmalignant cells, forming circulating tumor microemboli (CTM). Cell-cell interactions are key regulators within CTM that convey enhanced metastatic properties, including improved cell survival, immune evasion, and effective extravasation into distant organs. However, the cellular and molecular mechanism of CTM formation, as well as the biology of interactions between tumor cells and immune cells, platelets, and stromal cells in the circulation, remains to be determined. Here, we review the current literature on cell-cell interactions in homotypic and heterotypic CTM and provide perspectives on therapeutic strategies to attenuate CTM-mediated metastasis by targeting cell-cell interactions.

Identification of epithelial and mesenchymal circulating tumor cells in clonal lineage of an aggressive prostate cancer case

Little is known about the complexity and plasticity of circulating tumor cell (CTC) biology in different compartments of the fluid microenvironment during tumor metastasis. Here we integrated phenomics, genomics, and targeted proteomics to characterize CTC phenotypic and genotypic heterogeneity in paired peripheral blood (PB) and bone marrow aspirate (BMA) from a metastatic prostate cancer patient following the rapid disease progression, using the High-Definition Single Cell Assay 3.0 (HDSCA3.0). Uniquely, we identified a subgroup of genetically clonal CTCs that acquired a mesenchymal-like state and its presence was significantly associated with one subclone that emerged along the clonal lineage. Higher CTC abundance and phenotypic diversity were observed in the BMA than PB and differences in genomic alterations were also identified between the two compartments demonstrating spatial heterogeneity. Single cell copy number profiling further detected clonal heterogeneity within clusters of CTCs (also known as microemboli or aggregates) as well as phenotypic variations by targeted proteomics. Overall, these results identify epithelial and mesenchymal CTCs in the clonal lineage of an aggressive prostate cancer case and also demonstrate a single cell multi-omic approach to deconvolute the heterogeneity and association of CTC phenotype and genotype in multi-medium liquid biopsies of metastatic prostate cancer.

Liquid Biopsy Landscape in Patients with Primary Upper Tract Urothelial Carcinoma

Urothelial carcinomas (UCs) are a broad and heterogeneous group of malignancies, with the prevalence of upper tract urothelial carcinoma (UTUC) being rare, accounting for only 5-10% of total malignancies. There is a need for additional toolsets to assist the current clinical paradigm of care for patients with UTUC. As a non-invasive tool for the discovery of cancer-related biomarkers, the liquid biopsy has the potential to represent the complex process of tumorigenesis and metastasis. Herein, we show the efficacy of the liquid biopsy as a source of biomarkers for detecting UTUC. Using the third-generation high-definition single-cell assay (HDSCA3.0) workflow, we investigate liquid biopsy samples collected from patients with UTUC and normal donors (NDs) to provide critical information regarding the molecular and morphological characteristics of circulating rare events. We document several important findings from the liquid biopsy analysis of patients diagnosed with UTUC prior to surgery: (1) Large extracellular vesicles (LEVs) and circulating tumor cells (CTCs) are detectable in the peripheral blood. (2) The rare-event profile is highly heterogeneous. (3) Clinical data elements correlate with liquid biopsy analytes. Overall, this study provides evidence for the efficacy of the liquid biopsy in understanding the biology of UTUC with the future intent of informing clinical decision making, ultimately improving patient outcomes.

Preoperative Platelet Count Correlates With Postoperative Perineural Invasion on Specimen in Patients Treated With Radical Prostatectomy

Objective

It has been reported that perineural invasion (PNI) after radical prostatectomy (RP) is associated with unfavorable prostate cancer (PCa) prognosis. However, the clinicopathological factors especially hematological parameters that influenced PNI remain unknown. Our aim was to explore the relationship between clinicopathological parameters and PNI in patients who underwent RP.

Methods

A total of 348 patients with PCa who underwent RP at our center between 2018 and 2021 were consecutively collected. We divided them into non-PNI and PNI groups based on PNI status and compared clinicopathological characteristics including hematological parameters between non-PNI and PNI groups. The association of clinicopathological parameters including whole blood parameters, age, body mass index (BMI), hypertension, diabetes mellitus, prostate-specific antigen (PSA), ISUP (International Society of Urological Pathology) grade, pathological stage T (pT), and neoadjuvant hormonal therapy (NHT) with PNI was determined by univariate and multivariate logistic regression analyses.

Results

The pathological results of the RP specimen consisted of 254 (73.0%) patients with PNI and 94 (27.0%) cases without PNI. The level of PSA, percentages of advanced pT and grade, positive surgical margin rate, and vessel carcinoma embolus rate were significantly higher in the PNI group when compared with non-PNI counterpart (p = 0.007, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). Among the whole blood parameters, only platelet count and plateletcrit were significantly different [216 (178.8–252.0) vs. 200.5 (173.5–236.5), p = 0.04; 0.0021 (0.0018–0.0025) vs. 0.0020 (0.0017–0.0023), p = 0.008, respectively]. Univariate logistic regression analysis demonstrated that platelet, ISUP, and pT were all positively correlated with the presence of PNI (T3 vs. T1, odds ratio (OR) = 2.029, p = 0.020; OR = 1.697, p < 0.001; OR = 3.836, p < 0.001). In the stepwise multivariate regression analysis, the association between platelet and PNI remained significant (T2 vs. T1, OR = 2.171, 95% CI: 1.082–4.354, p = 0.029; T3 vs. T1, OR = 2.595, 95% CI: 1.259–5.349, p = 0.010) after adjusting for confounding factors including age, BMI, hypertension, diabetes mellitus, PSA, ISUP, pT, and NHT.

Conclusions

The study first revealed that platelet count rather than other whole blood parameters was independently associated with the presence of PNI in patients with PCa, suggesting that platelets might play an essential role in PCa aggressiveness.

Enrichment-Free Single-Cell Detection and Morphogenomic Profiling of Myeloma Patient Samples to Delineate Circulating Rare Plasma Cell Clones

Multiple myeloma is an incurable malignancy that initiates from a bone marrow resident clonal plasma cell and acquires successive mutational changes and genomic alterations, eventually resulting in tumor burden accumulation and end-organ damage. It has been recently recognized that myeloma secondary genomic events result in extensive sub-clonal heterogeneity both in localized bone marrow areas and circulating peripheral blood plasma cells. Rare genomic subclones, including myeloma initiating cells, could be the drivers of disease progression and recurrence. Additionally, evaluation of rare myeloma cells in blood for disease monitoring has numerous advantages over invasive bone marrow biopsies. To this end, an unbiased method for detecting rare cells and delineating their genomic makeup enables disease detection and monitoring in conditions with low abundant cancer cells. In this study, we applied an enrichment-free four-plex (CD138, CD56, CD45, DAPI) immunofluorescence assay and single-cell DNA sequencing for morphogenomic characterization of plasma cells to detect and delineate common and rare plasma cells and discriminate between normal and malignant plasma cells in paired blood and bone marrow aspirates from five patients with newly diagnosed myeloma (N = 4) and monoclonal gammopathy of undetermined significance (n = 1). Morphological analysis confirms CD138+CD56+ cells in the peripheral blood carry genomic alterations that are clonally identical to those in the bone marrow. A subset of altered CD138+CD56- cells are also found in the peripheral blood consistent with the known variability in CD56 expression as a marker of plasma cell malignancy. Bone marrow tumor clinical cytogenetics is highly correlated with the single-cell copy number alterations of the liquid biopsy rare cells. A subset of rare cells harbors genetic alterations not detected by standard clinical diagnostic methods of random localized bone marrow biopsies. This enrichment-free morphogenomic approach detects and characterizes rare cell populations derived from the liquid biopsies that are consistent with clinical diagnosis and have the potential to extend our understanding of subclonality at the single-cell level in this disease. Assay validation in larger patient cohorts has the potential to offer liquid biopsy for disease monitoring with similar or improved disease detection as traditional blind bone marrow biopsies.

Characterization of Cellular and Acellular Analytes from Pre-Cystectomy Liquid Biopsies in Patients Newly Diagnosed with Primary Bladder Cancer

Urinary bladder cancer (BCa) is the 10th most frequent cancer in the world, most commonly found among the elderly population, and becomes highly lethal once cells have spread from the primary tumor to surrounding tissues and distant organs. Cystectomy, alone or with other treatments, is used to treat most BCa patients, as it offers the best chance of cure. However, even with curative intent, 29% of patients experience relapse of the cancer, 50% of which occur within the first year of surgery. This study aims to use the liquid biopsy to noninvasively detect disease and discover prognostic markers for disease progression. Using the third generation high-definition single cell assay (HDSCA3.0), 50 bladder cancer patient samples and 50 normal donor (ND) samples were analyzed for circulating rare events in the peripheral blood (PB), including circulating tumor cells (CTCs) and large extracellular vesicles (LEVs). Here, we show that (i) CTCs and LEVs are detected in the PB of BCa patients prior to cystectomy, (ii) there is a high heterogeneity of CTCs, and (iii) liquid biopsy analytes correlate with clinical data elements. We observed a significant difference in the incidence of rare cells and LEVs between BCa and ND samples (median of 74.61 cells/mL and 30.91 LEVs/mL vs. 34.46 cells/mL and 3.34 LEVs/mL, respectively). Furthermore, using classification models for the liquid biopsy data, we achieved a sensitivity of 78% and specificity of 92% for the identification of BCa patient samples. Taken together, these data support the clinical utility of the liquid biopsy in detecting BCa, as well as the potential for predicting cancer recurrence and survival post-cystectomy to better inform treatment decisions in BCa care.