miR-182, miR-221 and miR-222 are potential urinary extracellular vesicle biomarkers for canine urothelial carcinoma.

Current diagnostic methods for canine urothelial carcinoma (UC) are technically challenging or can lack specificity, hence there is a need for novel biomarkers of UC. To this end, we analysed the microRNA (miRNA) cargo of extracellular vesicles (EVs) from urine samples of dogs with UC to identify candidate miRNA biomarkers. Urine was fractionated using ultrafiltration combined with size-exclusion chromatography and small RNA sequencing analysis was performed on both the EV enriched and (EV free) protein fractions. A greater number of candidate miRNA biomarkers were detected in the EV fraction than the protein fraction, and further validation using droplet digital PCR (ddPCR) was performed on the EV enriched fraction of a second cohort of dogs with UC which indicated that miR-182, miR-221 and miR-222 were significantly overrepresented in dogs with UC when compared with healthy dogs and dogs with urinary tract infections. Pathway analysis confirmed that these three miRNAs are involved in cancer. In addition, their potential downstream gene targets were predicted and PIK3R1, a well-known oncogene is likely to be a shared target between miRNA-182 and miRNA-221/222. In summary, this study highlights the potential of urinary EV-associated miRNAs as a source of biomarkers for the diagnosis of canine UC.

Primary exophytic urothelial carcinoma of the bladder: A case report.

RATIONALE: Bladder urothelial carcinoma (UC) is a common urinary system tumor that is generally diagnosed by cystoscopy combined with pathological biopsy. However, complete exophytic UC of the bladder is very rare and difficult to diagnose. Early diagnosis and accurate identification of such tumors, followed by aggressive surgical treatment, is essential for the management of these patients. PATIENT CONCERNS: An 84-year-old man was admitted to the hospital with dysuria, a poor diet, and significant weight loss. DIAGNOSIS: Pelvic computed tomography and magnetic resonance imaging revealed an exteriophytic round mass on the right lateral wall of the bladder. Cystoscopy revealed a necrotic mass on the right lateral wall of the bladder cavity, and no tumor cells were found following the biopsy. The tumor was removed via partial cystectomy, and the pathological result indicated high-grade muscle-invasive UC. INTERVENTIONS: The patient refused radical cystectomy and underwent laparoscopic partial cystectomy plus pelvic lymph node dissection followed by cisplatin plus gemcitabine chemotherapy. OUTCOMES: The patient's mental state and appetite were significantly improved after the urinary tube was removed 1 week after surgery. His general state was significantly improved after 1 month of follow-up but died of acute cerebral infarction 3 months after surgery. LESSONS: UC of the bladder may grow completely out of the bladder without symptoms such as gross hematuria; thus, early diagnosis is difficult. For high-risk individuals, regular imaging tests may help to detect tumors early. Partial cystectomy is a reliable surgical modality for bladder preservation in such patients.

Clinical evolution of bladder carcinosarcoma: A case report and literature review.

RATIONALE: Bladder carcinosarcoma (BC) is a malignant tumor composed of a mixture of malignant epithelial and stromal components. Carcinosarcoma mostly occurs in the upper respiratory tract and upper gastrointestinal tract and is less common in the urinary system. The incidence of malignant tumors of the urinary system is <3%. It rarely occurs in the bladder and accounts for approximately 0.31% of all malignant bladder tumors. A literature review and this report will help to further improve our understanding, diagnosis, and treatment of bladder carcinosarcoma (BC). PATIENT CONCERN: We describe the case of an 80-year-old female patient who was admitted to the hospital with a history of intermittent hematuria for 3 years. Furthermore, total cystectomy was refused when a BC was diagnosed. Palliative resection surgery was necessary because of the recurrent hematuria and abdominal pain. DIAGNOSES: Pathologically confirmed BC after surgery. INTERVENTIONS: The patient's first transurethral resection of bladder tumor (TURBT) was diagnosed as BC. However, the patient refused a total cystectomy. Two months after intravesical treatment with epirubicin, bladder tumor recurrence was observed during follow-up cystoscopy. The patient underwent a second TURBT for hemostatic treatment due to persistent hematuria. Due to hematuria and abdominal pain, a third TURBT was performed to reduce tumor size and stop bleeding. Finally, tumor recurrence resulted in bilateral hydronephrosis, and the patient underwent bilateral renal catheter drainage guided by B-ultrasound. OUTCOMES: Bladder carcinosarcoma caused uremia, electrolyte imbalance, and sepsis. Approximately 19 months after the discovery of the tumor, the patient died. LESSONS: Radical bladder resection is recommended once a BC is diagnosed. By reporting the cases and reviewing the literature in the database, we will summarize the epidemiology, origin, etiology, clinical features, existing treatments, and prognostic factors of BC, and propose new prospects for BC therapy.

Novel method for detecting frequent TERT promoter hot spot mutations in bladder cancer samples.

Telomerase reverse transcriptase promoter (TERTp) mutations are frequently targeted tumor markers, however, they reside in regions with high GC content, which poses challenges when examined with simple molecular techniques or even with next-generation sequencing (NGS). In bladder cancer (BC), TERTp mutations are particularly frequent, however, none of the available tools have demonstrated efficacy in detecting TERTp mutations via a simple noninvasive technique. Therefore, we developed a novel PCR-based method for the detection of the two most common TERTp mutations and demonstrated its use for the analysis of BC samples. The developed SHARD-PCR TERTp mutation detection technique requires PCR and restriction digestion steps that are easily implementable even in less well-equipped laboratories. Cell lines with known mutational status were utilized for method development. Matching urine and tumor tissue samples from BC patients were analyzed, and the results were validated by next-generation sequencing. Analysis of eighteen urine and corresponding tumor tissue samples by SHARD-PCR revealed perfect matches in sample pairs, which paralleled the corresponding NGS results: fourteen samples exhibited mutations at the -124 position, two samples showed mutations at the -146 position, and no mutations were detected in two samples. Our study serves as a proof-of-concept and is limited by its small sample size, nonetheless, it demonstrates that SHARD-PCR is a simple, economic and highly reliable method for detecting TERTp mutations, which are common in different cancer types. For bladder cancer, SHARD-PCR can be performed with the use of noninvasive samples and could replace or complement currently used techniques.

Inflammatory myofibroblastic tumor in the urinary bladder in a dog.

An 8-year-old castrated male Maltese dog was presented with a urinary bladder mass, urolithiasis, and hematuria. A solitary, pedunculated, intraluminal mass on the caudodorsal wall was identified with extensive irregular bladder wall thickening, and the mass was surgically removed. Postoperative histopathology demonstrated a submucosal lesion comprising spindle cells with marked inflammatory cell infiltration, without malignant changes. Immunohistochemical staining revealed vimentin and desmin positivity in the mass. An inflammatory myofibroblastic tumor (IMT) was definitively diagnosed. No recurrence was observed during a 43-month follow-up period. Although IMTs are rare in dogs, they should be considered a differential diagnosis for mass-like urinary bladder lesions accompanying a chronic inflammatory disease process. Key clinical message: Canine IMT should be included in the differential diagnoses of bladder masses, especially when dogs exhibit chronic irritation and inflammation.

Tumeur myofibroblastique inflammatoire de la vessie chez un chienUn chien maltais mâle castré de 8 ans a été présenté avec une masse à la vessie, une lithiase urinaire et une hématurie. Une masse intraluminale pédonculée solitaire sur la paroi caudodorsale a été identifiée avec un épaississement important et irrégulier de la paroi vésicale, et la masse a été retirée chirurgicalement. L'histopathologie postopératoire a mis en évidence une lésion à la sous-muqueuse comprenant des cellules fusiformes avec une infiltration cellulaire inflammatoire marquée, sans modification maligne. La coloration immunohistochimique a révélé une positivité à la vimentine et à la desmine dans la masse. Une tumeur myofibroblastique inflammatoire (IMT) a été définitivement diagnostiquée. Aucune récidive n'a été observée au cours d'une période de suivi de 43 mois. Bien que les IMT soient rares chez le chien, ils doivent être considérés comme un diagnostic différentiel des lésions de la vessie de type masse accompagnant un processus de maladie inflammatoire chronique.Message clinique clé:L'IMT canine doit être incluse dans les diagnostics différentiels des masses vésicales, en particulier lorsque les chiens présentent une irritation et une inflammation chroniques.(Traduit par Dr Serge Messier).

Hypermethylated TAGMe as a universal-cancer-only methylation marker and its application in diagnosis and recurrence monitoring of urothelial carcinoma.

BACKGROUND: Urothelial carcinoma (UC) is the second most common urological malignancy. Despite numerous molecular markers have been evaluated during the past decades, no urothelial markers for diagnosis and recurrence monitoring have shown consistent clinical utility. METHODS: The methylation level of tissue samples from public database and clinical collected were analyzed. Patients with UC and benign diseases of the urinary system (BUD) were enrolled to establish TAGMe (TAG of Methylation) assessment in a training cohort (n = 567) using restriction enzyme-based bisulfite-free qPCR. The performance of TAGMe assessment was further verified in the validation cohort (n = 198). Urine samples from 57 UC patients undergoing postoperative surveillance were collected monthly for six months after surgery to assess the TAGMe methylation. RESULTS: We identified TAGMe as a potentially novel Universal-Cancer-Only Methylation (UCOM) marker was hypermethylated in multi-type cancers and investigated its application in UC. Restriction enzyme-based bisulfite-free qPCR was used for detection, and the results of which were consistent with gold standard pyrosequencing. Importantly, hypermethylated TAGMe showed excellent sensitivity of 88.9% (95% CI: 81.4-94.1%) and specificity of 90.0% (95% CI: 81.9-95.3%) in efficiently distinguishing UC from BUD patients in urine and also performed well in different clinical scenarios of UC. Moreover, the abnormality of TAGMe as an indicator of recurrence might precede clinical recurrence by three months to one year, which provided an invaluable time window for timely and effective intervention to prevent UC upstaging. CONCLUSION: TAGMe assessment based on a novel single target in urine is effective and easy to perform in UC diagnosis and recurrence monitoring, which may reduce the burden of cystoscopy. Trial registration ChiCTR2100052507. Registered on 30 October 2021.

Diagnostic performance of photodynamic diagnosis with oral 5-aminolevulinic acid for upper tract- and bladder urothelial carcinoma: a single-centre, retrospective analysis.

PURPOSE: To compare the diagnostic performance of photodynamic diagnosis (PDD) enhanced with oral 5-aminolaevulinic acid between the suspected upper tract urothelial carcinoma (UTUC) and bladder urothelial carcinoma (BUC) cases. METHODS: This retrospective study included 18 patients with suspected UTUC who underwent ureteroscopy (URS) with oral 5-ALA in the PDD-URS cohort between June 2018 and January 2019; and 110 patients with suspected BUC who underwent transurethral resection of bladder tumour (TURBT) in the PDD-TURBT cohort between January 2019 and March 2023. Sixty-three and 708 biopsy samples were collected during diagnostic URS and TURBT, respectively. The diagnostic accuracy of white light (WL) and PDD in the two cohorts was evaluated, and false PDD-positive samples were pathologically re-evaluated. RESULTS: The area under the receiver operating characteristic curve (AUC) of PDD was significantly superior to that of WL in both cohorts. The per biopsy sensitivity, specificity, and positive and negative predictive values of PDD in patients in the PDD-URS and PDD-TURBT cohorts were 91.2 vs. 71.4, 75.9 vs. 75.3, 81.6 vs. 66.3, and 88.0 vs. 79.4%, respectively. The PDD-URS cohort exhibited a higher AUC than did the PDD-TURBT cohort (0.84 vs. 0.73). Seven of four false PDD-positive samples (57.1%) in the PDD-URS cohort showed potential precancerous findings compared with eight of 101 (7.9%) in the PDD-TURBT cohort. CONCLUSION: The diagnostic performance of PDD in the PDD-URS cohort was at least equivalent to that in the PDD-TURBT cohort.

Case series of urachal adenocarcinoma: Imaging features.

ABSTRACT: Urachal adenocarcinoma is an unusual and aggressive form of bladder cancer that arises from urachus, a midline fibrous remnant of allantois. Experience with diagnosing them is limited and differentiating urachal adenocarcinoma from other urachal pathologies like infected urachal cysts may be difficult at times. Differentials of urachal anomalies can be narrowed down by proper assessment of patient demographics, clinical details, lesion morphology, and imaging findings. With this case series of five patients of urachal adenocarcinoma, we have tried describing their clinical manifestation and imaging appearances.

Machine learning assisted microfluidics dual fluorescence flow cytometry for detecting bladder tumor cells based on morphological characteristic parameters.

BACKGROUND: Bladder cancer (BC) is the most common malignant tumor and has become a major public health problem, leading the causes of death worldwide. The detection of BC cells is of great significance for clinical diagnosis and disease treatment. Urinary cytology based liquid biopsy remains high specificity for early diagnosis of BC, however, it still requires microscopy examination which heavily relies on manual operations. It is imperative to investigate the potential of automated and indiscriminate cell differentiation technology to enhance the sensitivity and efficiency of urine cytology. RESULTS: Here, we developed a machine learning algorithm empowered dual-fluorescence flow cytometry platform (µ-FCM) for urinary cytology analysis. A phenotype characteristic parameter (CP) which correlated with the size of the cell and nucleus was defined to achieve the differentiation of the BC cells and uroepithelial cells with high throughput and high accuracy. Based on CP analysis, SV-HUC-1 cells were almost differentiated from EJ cells and effectively reduced the overlap with 5637 cells. To further differentiate SV-HUC-1 cells and 5637 cells, support vector machine (SVM) machine learning algorithm was optimized to assist data analysis with the highest accuracies of 84.7 % for cell differentiation including the specificity of 91.0 % and the sensitivity of 75.0 %. Furthermore, the false positive rate (FPR) compensation enabled the detection rates of rare BC cells predicted by the well-trained SVM model were close to the true proportions with the recognition error in 0.4 % for the tumor cells. SIGNIFICANCE: As a proof of concept, the developed µ-FCM system successfully demonstrates the capacity to identify the distribution of exfoliated cells in real urine samples. This system underscores the significance of integrating AI with microfluidics to perform high-throughput phenotyping of exfoliated cells, offering a pathway toward scalable, efficient, and automatic microfluidic systems in the fields of both biosensing and in vitro diagnosis of BC.

[A real-world study of the clinical application of the Paris system for reporting urinary cytology in cancer hospital].

Objectives: To evaluate the clinical value of the Paris system for reporting urinary cytology (TPS) in the diagnosis of urothelial carcinoma (UC). Methods: A total of 1 744 cytological diagnostic records (from 751 cases) were collected retrospectively. All specimens were voided urines and histopathology as the gold standard. The sensitivity and specificity of urinary cytological diagnosis of UC and risk of high grade malignant (ROHM) in each diagnostic category were compared. Results: There were 360 cases with histopathology. The percentage of negative for high-grade urothelial carcinoma (NHGUC) was 30.1% (226/751), atypical urothelial cells (AUC) was 29.8% (224/751), suspicious for high-grade urothelial carcinoma (SHGUC) was 16.8% (126/751), high grade urothelial carcinoma (HGUC) was 21.2% (159/751), and non-urothelial malignancy (NUM) was 2.1% (16/751). The histpathologic ROHM corresponding to each cytological diagnosis category were 27.3% for NHGUC, 32.7% for AUC, 74.7% for SHGUC, 96.6% for HGUC and 100.0% for NUM, respectively. ROHM of SHGUC was significantly higher than that of AUC group, and the difference between the two groups was statistically significant (P＜0.001). ROHM of HGUC group was significantly higher than that of SHGUC group, and the difference was statistically significant (P＜0.001). With SHGUC as the cut-off value, the sensitivity and specificity of cytological diagnosis of HGUC were 76.7% (165/215) and 85.7% (18/21), and with HGUC as the cut-off value, the sensitivity and specificity of cytological diagnosis of HGUC were 53.0% (114/215) and 100.0% (21/21), respectively. Conclusions: Urine cytology has high sensitivity and specificity in the diagnosis of HGUC. The malignant risk of TPS varies with different diagnosis category. The high malignant risk population in cancer hospital leads to the relatively high malignant proportion and ROHM in each diagnosis category. Urinary cytology TPS reporting system is helpful to clinical management and has good clinical application value.

The clinical value of rapidly detecting urinary exosomal lncRNA RMRP in bladder cancer with an RT-RAA-CRISPR/Cas12a method.

BACKGROUND AND AIMS: Bladder cancer (BCa) is a highly aggressive malignancy of the urinary system. Timely detection is imperative for enhancing BCa patient prognosis. MATERIALS AND METHODS: This study introduces a novel approach for detecting long non-coding RNA (lncRNA) Mitochondrial RNA Processing Endoribonuclease (RMRP) in urine exosomes from BCa patients using the reverse transcription recombinase-aided amplification (RT-RAA) and clustered regularly interspaced short palindromic repeats and associated Cas12a proteins (CRISPR/Cas12a) technique. Various statistical methods were used to evaluate its diagnostic value for BCa. RESULTS: The specificity of urine exosomal RMRP detection for BCa diagnosis was enhanced by using RT-RAA combined with CRISPR/Cas12a. The testing process duration was reduced to 30 min, which supports rapid detection. Moreover, this approach allows the identification of target signals in real-time using blue light, facilitating immediate detection. In clinical sample analysis, this methodology exhibited a high level of diagnostic efficacy. This was evidenced by larger area under the curve values with receiver operating characteristic curve analysis compared with using traditional RT-qPCR methods, indicating superior diagnostic accuracy and sensitivity. Furthermore, the combined analysis of RMRP expression in urine exosomes detected by RT-RAA-CRISPR/Cas12a and NMP-22 expression may further enhance diagnostic accuracy. CONCLUSIONS: The RT-RAA-CRISPR/Cas12a technology is a swift, sensitive, and uncomplicated method for nucleic acid detection. Because of its convenient and non-invasive sampling approach, user-friendly operation, and reproducibility, this technology is very promising for automated detection and holds favorable application possibilities within clinical environments.

The UF-5000 Atyp.C parameter is an independent risk factor for bladder cancer.

Bladder carcinoma (BC) accounts for > 90% of all urothelial cancers. Pathological diagnosis through cytoscopic biopsy is the gold standard, whereas non-invasive diagnostic tools remain lacking. The "Atyp.C" parameter of the Sysmex UF-5000 urine particle analyzer represents the ratio of nucleus to cytoplasm and can be employed to detect urinary atypical cells. The present study examined the association between urinary Atyp.C values and BC risk. This two-center, retrospective case-control study identified clinical primary or newly recurrent BC (study period, 2022-2023; n = 473) cases together with controls with urinary tract infection randomly matched by age and sex (1:1). Urinary sediment differences were compared using non-parametric tests. The correlations between urinary Atyp.C levels and BC grade or infiltration were analyzed using Spearman's rank correlation. The BC risk factor odds ratio of Atyp.C was calculated using conditional logistic regression, and potential confounder effects were adjusted using stepwise logistic regression (LR). Primary risk factors were identified by stratified analysis according to pathological histological diagnosis. The mean value of urinary Atyp.C in BC cases (1.30 ± 3.12) was 8.7 times higher than that in the controls (0.15 ± 0.68; P < 0.001). Urinary Atyp.C values were positively correlated with BC pathological grade and invasion (r = 0.360, P < 0.001; r = 0.367, P < 0.001). Urinary Atyp.C was an independent risk factor for BC and closely related with BC pathological grade and invasion. Elevated urinary Atyp.C values was an independent risk factor for BC. Our findings support the use of Atyp.C as a marker that will potentially aid in the early diagnosis and long-term surveillance of new and recurrent BC cases.

Target recycle initiated entropy driven assembly strategy for sensitive, enzyme-free, and portable miRNA detection.

MicroRNA (miRNA) is a pivotal biomarker in the diagnosis of various cancers, including bladder cancer (BCa). Despite their significance, the low abundance of miRNA presents a substantial challenge for sensitive and reliable detection. We introduce an innovative, highly sensitive assay for miRNA expression quantification that is both enzyme-free and portable. This method leverages the synergy of target recycling and entropy-driven assembly (EDA) for enhanced sensitivity and specificity. The proposed method possesses several advantages, including i) dual signal amplification through target recycling and EDA, which significantly boosts sensitivity with a lower limit of detection of 2.54 fM; ii) elimination of enzyme requirements, resulting in a cost-effective and stable signal amplification process; and iii) utilization of a personal glucose meter (PGM) for signal recording, rendering the method portable and adaptable to diverse settings. In summary, this PGM-based approach holds promising potential for clinical molecular diagnostics, offering a practical and efficient solution for miRNA analysis in cancer detection.

[Exploration of the clinical transformation application of the artificial intelligence diagnosis system for bladder cancer based on cystoscopy].

This study aims to explore the possibility and bottleneck of clinical translation for an artificial intelligence (AI) diagnosis system for bladder cancer based on cystoscopy.We retrospectively collected videos of 101 bladder cancer patients from January to November 2023, at Sun Yat-sen Memorial Hospital, Sun Yat-sen University. Among these patients, with a median age of 63 years and 81.0% were male. The bladder cancer AI diagnosis system was utilized for diagnosis, and the accuracy of diagnoses from the videos was assessed. Additionally, a surgical evaluation scale was formulated to evaluate the quality of the videos, simulating clinical usage.The final test results showed a system sensitivity of 97.8%, a positive predictive value of 81.7%, specificity of 54.2%, and a negative predictive value of 92.3%. Furthermore, the surgical evaluation scale scores ranged from 3.96 to 4.69, indicating the feasibility of clinical application for this system.This study further quantitatively validated the accuracy of an artificial intelligence system using cystoscopy videos and assessed the potential for clinical application.

Choline Phosphate-Grafted Nanozymes as Universal Extracellular Vesicle Probes for Bladder Cancer Detection.

Urinary extracellular vesicles (uEVs) are regarded as highly promising liquid-biopsy biomarkers for the early diagnosis and prognosis of bladder cancer (BC). However, detection of uEVs remains technically challenging owing to their huge heterogeneity and ultralow abundance in real samples. We herein present a choline phosphate-grafted platinum nanozyme (Pt@CP) that acts as a universal EV probe for the construction of a high-throughput and high-sensitivity immunoassay, which allowed multiplex profiling of uEV protein markers for BC detection. With the Pt@CP-based immunoassays, three uEV protein markers (MUC-1, CCDC25, and GLUT1) were identified for BC, by which the BC cases (n = 48), cystitis patients (n = 27), and healthy donors (n = 24) were discriminated with high clinical sensitivity and specificity (area under curve = 98.3%). For the BC cases (n = 9) after surgery, the Pt@CP-based immunoassay could report the postoperative residual tumor that cannot be observed by cystoscopy, which is clinically significant for assessing BC recurrence. This work provides generally high sensitivity for EV detection, facilitating the discovery and clinical use of EV-based biomarkers.

[Urinary cytology for the detection of urothelial lesions]. / Rôle de la cytologie urinaire dans le dépistage des lésions urothéliales.

Urine cytology is a long-used technique for the detection of high grade neoplastic urothelial lesions. Since 2016, «The Paris System¼ classification has revolutionized this field by introducing a standardized terminology widely adopted by cytopathologists and urologists. In this article, we explain this classification and discuss its impact on the clinical management of patients with urothelial lesions, as well as its role in the secondary prevention of these lesions.

La cytologie urinaire est une technique utilisée depuis longtemps dans la détection des lésions urothéliales tumorales de haut grade. Depuis 2016, la classification «The Paris System¼ a révolutionné ce domaine en introduisant une terminologie standardisée largement adoptée par les cytopathologistes et les urologues. Dans cet article, nous expliquons cette classification et discutons de son impact sur la prise en charge clinique des lésions urothéliales, ainsi que son rôle dans la prévention secondaire de ces lésions.

LncRNA BCYRN1 as a Potential Therapeutic Target and Diagnostic Marker in Serum Exosomes in Bladder Cancer.

Bladder cancer (BC) is a common genitourinary malignancy that exhibits silent morbidity and high mortality rates because of a lack of diagnostic markers and limited effective treatments. Here, we evaluated the role of the lncRNA brain cytoplasmic RNA 1 (BCYRN1) in BC. We performed loss-of-function assays to examine the effects of BCYRN1 downregulation in T24 and BOY BC cells. We found that BCYRN1 downregulation significantly inhibited the proliferation, migration, invasion, and three-dimensional spheroid formation ability and induced apoptosis in BC cells. Additionally, gene set enrichment analysis (GSEA) using RNA sequences from tumor fractions showed that BCYRN1 downregulation decreased the expression of mRNAs associated with the cell cycle. These findings were supported by observations of G2/M arrest in flow cytometry assays. Finally, we examined the expression of serum exosomal BCYRN1 as a biomarker. Clinically, BCYRN1 expression in serum exosomes from patients with BC (n = 31) was significantly higher than that in healthy donors (n = 19; mean difference: 4.1-fold higher, p < 0.01). Moreover, in patients who had undergone complete resection of BC, serum exosomal BCYRN1 levels were significantly decreased (n = 8). Thus, serum exosomal BCYRN1 may be a promising diagnostic marker and therapeutic target in patients with BC.