Identification of Ppy-lineage cells as a novel origin of pancreatic ductal adenocarcinoma.

The Ppy gene encodes pancreatic polypeptide (PP) secreted by PP- or γ-cells, which are a subtype of endocrine cells localised mainly in the islet periphery. For a detailed characterisation of PP cells, we aimed to establish PP cell lines. To this end, we generated a mouse model harbouring the SV40 large T antigen (TAg) in the Rosa26 locus, which is expressed upon Ppy-promoter-mediated Cre-loxP recombination. Whereas Insulin1-CreERT-mediated TAg expression in beta cells resulted in insulinoma, surprisingly, Ppy-Cre-mediated TAg expression resulted in the malignant transformation of Ppy-lineage cells. These mice showed distorted islet structural integrity at 5 days of age compared with normal islets. CK19+ duct-like lesions contiguous with the islets were observed at 2 weeks of age, and mice developed aggressive pancreatic ductal adenocarcinoma (PDAC) at 4 weeks of age, suggesting that PDAC can originate from the islet/endocrine pancreas. This was unexpected as PDAC is believed to originate from the exocrine pancreas. RNA-sequencing analysis of Ppy-lineage islet cells from 7-day-old TAg+ mice showed a downregulation and an upregulation of endocrine and exocrine genes, respectively, in addition to the upregulation of genes and pathways associated with PDAC. These results suggest that the expression of an oncogene in Ppy-lineage cells induces a switch from endocrine cell fate to PDAC. Our findings demonstrate that Ppy-lineage cells may be an origin of PDAC and may provide novel insights into the pathogenesis of pancreatic cancer, as well as possible therapeutic strategies. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Comprehensive analysis of perioperative hypotension in photodynamic diagnosis-assisted transurethral resection of bladder tumor with 5-aminolevulinic acid.

OBJECTIVE: Intraoperative hypotension remains a serious adverse event of photodynamic diagnosis-assisted transurethral resection of bladder tumor with oral administration of 5-aminolevulinic acid. We conducted a re-analysis of perioperative hypotension in photodynamic diagnosis-assisted transurethral resection of the bladder tumor with oral 5-aminolevulinic acid to ascertain its safety. METHODS: A total of 407 cases who underwent transurethral resection of bladder tumors in our institution were reviewed (274 cases for the PDD group with photodynamic diagnosis and 133 for the white light (WL) group without). A classification of hypotension severity was devised to identify risk factors for clinically troublesome hypotension. The distribution of hypotension severity in each of the PDD and WL groups was compared. Additionally, the patient background and perioperative data by hypotension severity were compared only in the PDD group. RESULTS: More patients with moderate and severe hypotension were noted in the PDD group. The renal function was lower with increasing hypotension severity in the PDD group. More patients on general anesthesia were included in the mild and moderate hypotension group, whereas more patients on spinal anesthesia were included in the severe hypotension group. Furthermore, the frequency of side effects other than hypotension tended to increase with hypotension severity. CONCLUSIONS: Renal function impairment and the other adverse effects of 5-aminolevulinic acid may be risk factors for severe hypotension. Mild or moderate hypotension may be caused by general anesthesia and severe hypotension may be caused by spinal anesthesia. To elucidate specific risk factors, further case-control studies are warranted.

A seed link connector protruding into the bladder formed a bladder stone.

Introduction: Low-dose-rate brachytherapy is performed for localized prostate cancer. We report the first case of a bladder stone encompassing the seed migrated into the bladder in a patient treated with low-dose-rate brachytherapy. Case presentation: A man was diagnosed with prostate cancer and underwent low-dose-rate brachytherapy. After 2 months, dysuria occurred, and ultrasonography revealed a needle-shaped high-intensity protruding from the prostate into the bladder. Cystoscopy examination found a seed link connector. With the possibility of natural dissolution of the seed link, careful observation was chosen. However, 16 months later, hematuria occurred, and an X-ray revealed a bladder stone encompassing the seed. Compared with the X-ray right after seeding, the seed located near the right bladder neck had fallen. The seed was removed by transurethral bladder lithotripsy. Conclusion: Seeds should be carefully located within the prostate, otherwise a bladder stone may be formed encompassing the seed.

Bone Turnover Markers, n-Terminal Propeptide of Type I Procollagen and Tartrate-Resistant Acid Phosphatase Type 5b, for Predicting Castration Resistance in Prostate Cancer.

Bone is a common site of prostate cancer metastasis. Bone turnover markers n-terminal propeptide of type I procollagen (P1NP) and tartrate-resistant acid phosphatase type 5b (TRACP-5b) are highly sensitive to bone remodeling activity. However, their prognostic significance as markers of prostate cancer is unknown. This study retrospectively examined the usefulness of P1NP and TRACP-5b as prognostic biomarkers. Castration-resistant prostate cancer recurrence-free survival (CFS) was estimated using the Kaplan-Meier method. A predictive model for CFS was constructed using multivariate analysis. This study enrolled 255 patients diagnosed with prostate cancer at Kanazawa University Hospital. The median follow-up was 115.1 months. Patients with both high serum P1NP and TRACP-5b levels, defined as having a poor bone turnover category (BTC), had significantly shorter CFS. Multivariate analysis identified Gleason score, metastasis, and BTC poor as predictors for castration resistance in prostate cancer. Using these three factors, a prognostic model was established, categorizing patients into low-risk (no or one factor) and high-risk (two or three factors) groups. In the low-risk group, the median CFS was not reached, contrasting with 19.1 months in the high-risk group (hazard ratio, 32.23, p < 0.001). Combining P1NP and TRACP-5b may better predict castration resistance.

Does radical cystectomy have a better prognosis than bladder conservative treatment in the real world?

PURPOSE: To compare the prognosis and quality of life between radical cystectomy and bladder conservative treatment for muscle invasive bladder cancer in the real world. MATERIALS AND METHODS: Patients treated for muscle invasive bladder cancer without metastases were retrospectively evaluated for overall survival, progression-free survival, and rehospitalization. RESULTS: Of the 141 patients, 62 underwent bladder conservative treatment and 79 underwent radical cystectomy. Patients who underwent radical cystectomy had significantly better progression-free survival (HR: 1.83, 95% CI: 1.12-3.00; p < 0.01) and overall survival (HR: 1.82, 95% CI: 0.99-3.34; p = 0.03) than those who underwent conservative treatment. However, there was no significant difference in prognosis between patients who refused to undergo radical cystectomy and those who underwent. In addition, rehospitalization rates for complications and additional treatment were significantly higher in patients who received conservative treatment (69.3% vs. 34.2%; p < 0.01), and the length of hospital stay was also prolonged compared to patients who received radical cystectomy (26 vs. 9 days; p = 0.03). CONCLUSIONS: Overall, conservative treatment had a significantly poorer prognosis than radical cystectomy, but there was no significant difference in prognosis when comparing patients who refused radical cystectomy and received conservative treatment with those who received radical cystectomy. However, hospitalization rates and length of stay were significantly worse for patients who chose conservative treatment, which may lead to a decline in quality of life.

Procalcitonin in advanced urological cancer-bacterial versus non-bacterial infections: prospective cohort study.

OBJECTIVES: Patients with advanced cancer may develop bacterial infections (BI) as their general condition worsens, but general blood tests often find it difficult to distinguish them from non-bacterial infections (NBI). The present prospective study was undertaken to investigate the effectiveness of serum procalcitonin levels in distinguishing between BI and NBI in patients with advanced urological cancer. METHODS: This study prospectively evaluated patients diagnosed with locally advanced or metastatic or recurrent urological cancer in our department from September 2013 to December 2019. Body temperature was measured in the axilla and the measurement results were recorded. Febrile episodes of ≥38.0°C were analysed, and written patient consent was obtained at the onset of the fever. RESULTS: Of 75 patients enrolled in the present study, 90 febrile episodes were analysed. A total of 34 of 90 febrile episodes were regarded as BI, and the remaining 56 febrile episodes as NBI. The median procalcitonin value was significantly higher in the BI group (p=0.0015), while no significant difference was found between the two groups for white blood cell count and C reactive protein. Additionally, a white blood cell count of less than 1.0×10ˆ9/L resulted in BI in all cases. The procalcitonin receiver operating characteristic area under the curve was 0.710 (95% CI 0.586 to 0.83), excluding cases with white blood cell counts of <1.0 × 103/µL. CONCLUSIONS: Procalcitonin is a rapid and affordable marker for differentiation between BI and NBI in patients with advanced urological cancer.

Early chemotherapeutic intervention to avoid thyroidectomy in pediatric Langerhans cell histiocytosis with thyroid involvement accompanying tracheal stenosis: a report of two cases.

Thyroid involvement is rare in pediatric Langerhans cell histiocytosis (LCH). It may cause airway narrowing, leading to acute-onset respiratory distress. Severe cases may require emergent surgical interventions such as thyroidectomy, which should be avoided in children due to higher rates of complication, particularly in infancy. There is currently no consensus on the indications for surgical treatment in LCH with thyroid involvement. In this report, we describe the cases of two children who presented with tracheal stenosis caused by thyroid LCH, both of which were successfully treated by early induction of chemotherapy, and one of which was also treated for a shorter duration. Mutation analysis detected in-frame deletions of BRAF exon 12 in both cases. These cases suggest that timely diagnosis and administration of chemotherapy may alleviate severe airway obstruction and reduce the need for thyroidectomy in pediatric patients with thyroid LCH.

Role of Positive Biopsy Core Ratio in Prostate Cancer Patients.

BACKGROUND/AIM: The percentage of positive cores (PPC) is increasingly recognized as a prognostic factor in prostate cancer. However, the usefulness of PPC for patients undergoing androgen deprivation therapy (ADT) and high-risk group has not been adequately studied. PATIENTS AND METHODS: A retrospective analysis was conducted of 255 patients who underwent prostate biopsy (all-case group). We examined the efficacy of PPC as a prognostic biomarker. RESULTS: Eighty-nine patients were treated with ADT alone (ADT group), and 107 patients were classified as high-risk (high-risk group). The median duration of follow-up was 112.4 months, 85.3 months, and 110.0 months for the all-case, ADT, and high-risk groups, respectively. Patients with PPC >60% had significantly shorter prostate cancer-specific survival (CSS) and castration-resistant prostate cancer-free survival (CFS) in the all-case and ADT groups. In the high-risk group, patients with PPC >60% had shorter CFS but no difference in CSS. Multivariate analysis showed that significant independent predictors of prostate CSS were the presence of metastasis at diagnosis and PPC >60% in the all-case and ADT groups. CONCLUSION: PPC may be a prognostic factor in ADT treated and high-risk prostate patients.

Establishment of Pancreatic ß-Cell-Specific Gene Knockout System Based on CRISPR-Cas9 Technology With AAV8-Mediated gRNA Delivery.

The Cre-loxP system provides valuable resources to analyze the importance of tissue-specific gene knockout (KO), including pancreatic ß-cells associated with the pathogenesis of diabetes. However, it is expensive and time consuming to generate transgenic mice harboring floxed genes of interest and cross them with cell-specific Cre expression mice. We establish a ßCas9 system with mice expressing Cas9 in pancreatic ß-cells and adeno-associated virus 8 (AAV8)-mediated guide RNA (gRNA) delivery based on CRISPR-Cas9 technology to overcome those shortcomings. Interbreeding CAG-loxP-STOP-loxP (LSL)-Cas9 with Ins1-Cre mice generates normal glucose-tolerant ßCas9 mice expressing Cas9 with fluorescent reporter EGFP specifically in ß-cells. We also show significant ß-cell-specific gene KO efficiency with AAV8-mediated delivery of gRNA for EGFP reporter by intraperitoneal injection in the mice. As a proof of concept, we administered AAV8 to ßCas9 mice for expressing gRNA for Pdx1, a culprit gene of maturity-onset diabetes of the young 4. As reported previously, we demonstrate that those mice show glucose intolerance with transdifferentiation of Pdx1 KO ß-cells into glucagon-expressing cells. We successfully generated a convenient ß-cell-specific gene KO system with ßCas9 mice and AAV8-mediated gRNA delivery.

Novel α-Trifluoromethyl Chalcone Exerts Antitumor Effects Against Prostate Cancer Cells.

BACKGROUND/AIM: Despite treating advanced prostate cancer (PCa) with androgen deprivation therapy, it eventually progresses to castration-resistant PCa. Subsequently, taxanes are administered, but when PCa becomes resistant to taxanes, another treatment is needed, which has not yet been established. We previously synthesized a novel α-trifluoromethyl chalcone, YS71, and reported its antitumor effects against PCa cells. In this study, we confirmed its efficacy against androgen-sensitive, androgen-independent, and taxane-resistant PCa cells. MATERIALS AND METHODS: The PCa cell lines used were LNCaP, PC-3, DU145, PC-3-TxR (paclitaxel-resistant), PC-3-TxR/CxR (paclitaxel- and cabazitaxel-resistant), DU145-TxR, and DU145-TxR/CxR. The antiproliferative effects of YS71 were evaluated using proliferation assay. The reverse transcriptase transcription-polymerase chain reaction and western blot were performed to determine the expression level of androgen receptor (AR), whereas luciferase assay was performed to determine the AR activity. Furthermore, TUNEL assay and western blot were performed to investigate the mechanism of the antiproliferative effect. RESULTS: YS71 exerted a dose-dependent antitumor effect, inhibited AR activity, and induced apoptosis in all PCa cells in a dose-dependent manner. Western blot showed that YS71 increased the levels of apoptosis-related proteins, cleaved caspase-3, and cleaved PARP, and decreased the levels of the antiapoptotic proteins, Bcl-xL and Bcl-2. In addition, microarray analysis revealed that YS71 decreased several cancer-related genes. CONCLUSION: YS71 exhibits antitumor activity by inducing apoptosis in PCa cells, including taxane-resistant cells. It could be a potential future therapeutic option for hormone- and chemotherapy-resistant PCa.

Suppression of androgen receptor signaling induces prostate cancer migration via activation of the CCL20-CCR6 axis.

The suppression of androgen receptor (AR) expression exacerbates the migration potential of prostate cancer. This study identified a previously unrecognized regulation of the AR-controlled pathway that promotes migration potential in prostate cancer cells. Prostate cancer cells that pass through a transwell membrane (mig cells) have a higher migration potential with a decreased AR expression than parental cells. In this study, we aimed to elucidate the mechanism of migration enhancement associated with the suppression of AR signaling. Expression of C-C motif ligand 20 (CCL20) is upregulated in mig cells, unlike in the parental cells. Knockdown of AR with small interfering RNA (siAR) in LNCaP and C4-2B cells increased CCL20 secretion and enhanced the migration of cancer cells. Mig cells, CCL20-treated cells, and siAR cells promoted cell migration with an enhancement of AKT phosphorylation and Snail expression, while the addition of a C-C chemokine receptor 6 (CCR6, the specific receptor of CCL20) inhibitor, anti-CCL20 antibody, and AKT inhibitor suppressed the activation of AKT and Snail. With 59 samples of prostate cancer tissue, CCL20 secretion was profuse in metastatic cases despite low AR expression levels. Snail expression was associated with the expression of CCL20 and CCR6. A xenograft study showed that the anti-CCL20 antibody significantly inhibited Snail expression, thereby suggesting a new therapeutic approach for castration-resistant prostate cancer with the inhibition of the axis between CCL20 and CCR6.

Serum CCL2 Is a Prognostic Biomarker for Non-Metastatic Castration-Sensitive Prostate Cancer.

Purpose: Prostate-specific antigen (PSA) is a useful prostate cancer (PC) biomarker, but some cases reported that PSA does not correlate with the Gleason score. Serum chemokine (CC motif) ligand 2 (CCL2) has been reported to be a potential complementary PSA biomarker, but it remains unclear whether it can be applied to non-metastatic castration-sensitive prostate cancer (nmCSPC) or each section of the stages. Serum CCL2's usefulness was investigated as a prognostic nmCSPC biomarker in this study. Methods: Serum samples were collected from 379 patients who underwent prostate biopsy at Kanazawa University Hospital from 2007 to 2013. A total of 230 patients with nmCSPC were included in this study of the 255 patients with histologically diagnosed prostate cancer. The serum CCL2 efficacy as a prognostic nmCSPC biomarker was investigated retrospectively. Results: An independent significant predictor of worse OS was CCL2 ≥ 280 pg/dL and CRP ≥ 0.5 mg/dL in multivariate analysis. Gleason score ≥ 8 and CCL2 ≥ 280 pg/dL were independent significant predictors of CRPC-free survival (CFS) worsening in multivariate analysis. Serum CCL2 was a predictive biomarker for OS and CFS in nmCSPC. Furthermore, CCL2 ≥ 280 pg/mL patients had significantly worse visceral metastasis-free survival than those with CCL2 < 280 pg/mL. Conclusion: This study is the first to demonstrate serum CCL2 utility as a biomarker to predict OS and CFS in nmCSPC.

Usefulness of serum CCL2 as prognostic biomarker in prostate cancer: a long-term follow-up study.

OBJECTIVE: Prostate-specific antigen is considered the most useful biomarker for prostate cancer, but not in all cases. In a previous study, we have shown that a risk classification combining prostate-specific antigen ≥100 ng/mL and chemokine (CC motif) ligand 2 ≥ 320 pg/mL can predict survivals. We investigated the long-term usefulness of serum chemokine (CC motif) ligand 2 as a complementary biomarker to prostate-specific antigen and developed a novel risk classification system. METHODS: Serum samples were collected from 379 patients who underwent prostate biopsy at Kanazawa University Hospital between 2007 and 2013, and 255 patients with histologically diagnosed prostate cancer were included in this study. We retrospectively examined the efficacy of serum chemokine (CC motif) ligand 2 as a prognostic biomarker. RESULTS: Patients with chemokine (CC motif) ligand 2 ≥ 320 pg/mL exhibited a significantly shorter overall survival, prostate cancer-specific survival and castration-resistant prostate cancer-free survival than those with chemokine (CC motif) ligand 2 < 320 pg/mL. Multivariate analysis was performed to determine whether chemokine (CC motif) ligand 2 was a useful prognostic factor. Independent significant predictors of worse overall survival were prostate-specific antigen ≥ 100 ng/mL, Gleason score ≥ 8 and chemokine (CC motif) ligand 2 ≥ 320 pg/dL. Prognostic predictors of prostate cancer-specific survival or cancer-free survival in multivariate analysis were prostate-specific antigen ≥ 100 ng/mL and Gleason score ≥ 8. A novel risk classification system was created to predict overall survival in patients based on the number of risk factors present (chemokine (CC motif) ligand 2 ≥ 320 pg/mL, prostate-specific antigen ≥ 100 ng/mL, Gleason score ≥ 8). Scores 2 or 3, 1 and 0 indicated Poor, Intermediate and Good risk groups, respectively. CONCLUSIONS: This study demonstrated the utility of serum chemokine (CC motif) ligand 2 level as a predictive biomarker of long-term overall survival in prostate cancer. A novel risk classification system that predicts long-term overall survival based on the combined indications of chemokine (CC motif) ligand 2 level, prostate-specific antigen level and Gleason score may be a useful prognostic tool for prostate cancer.

Favorable Response of Pembrolizumab as Second-Line Therapy for Advanced Urothelial Carcinoma with Only Small Lesions to not be Considered Measurable by RECIST.

PURPOSE: Pembrolizumab is currently considered the standard second-line treatment for advanced urothelial carcinoma (UC). This study aimed to investigate the efficacy and safety of pembrolizumab in patients with advanced UC in real-world data, which is not well-reported. MATERIALS AND METHODS: The study included 97 patients with advanced UC whose lesions were classified according to the Response Evaluation Criteria in Solid Tumors (RECIST). The median age was 73 years. Nineteen patients (20%) with performance status (PS) 2-4 were included. The percentages of liver, lung, bone, and lymph node metastasis were 18%, 27%, 19%, and 76%, respectively. The efficacy, safety, and risk factors for prognosis were evaluated for patients with and without measurable lesions. RESULTS: The best response was complete response in nine patients (9%) and partial response in 16 patients (17%). The median progression-free survival and overall survival were 3.7 months (95% confidence interval [CI]: 2.8-4.7) and 11.8 months (95% CI: 6.7-17.0), respectively. Twenty-one (22%) patients had no measurable lesions per RECIST. In univariate and multivariate analysis, PS 2-4 and lesions by RECIST were identified as factors associated with short overall survival (OS). The median OS of 18.3 months in patients without lesions by RECIST was significantly longer than the median OS of 6.7 months in patients with lesions by RECIST (p = .012). CONCLUSION: We demonstrated that good PS 0-1 and no measurable lesions, especially small lesions, by RECIST were favorable prognostic factors in patients with advanced UC treated by pembrolizumab.

Blood Cell Count Biomarkers Predicting Efficacy of Pembrolizumab as Second-line Therapy for Advanced Urothelial Carcinoma.

BACKGROUND/AIM: To investigate the blood markers for predicting pembrolizumab efficacy in advanced urothelial carcinoma (UC). PATIENTS AND METHODS: This study included 91 advanced UC patients. The relationship between prognosis and markers from peripheral blood cell counts, including the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), and systemic inflammation response index (SIRI=monocytes × neutrophils/lymphocytes), was evaluated. RESULTS: Multivariate analysis indicated that pretreatment NLR and the 1-month-change NLR were both significantly associated with overall survival (OS) after pembrolizumab initiation. When the patients were divided into four groups according to calculated cutoffs using Cox proportional hazard model, the pretreatment NLR <2.9 and 1-month change NLR <+43% groups had a significantly better OS than the pretreatment NLR ≥2.9 and 1-month-change NLR ≥+43% groups. CONCLUSION: NLR, MLR, PLR and SIRI before pembrolizumab and 1-month-change NLR in advanced UC correlated with OS after pembrolizumab treatment.

Rubicon in pancreatic beta cells plays a limited role in maintaining glucose homeostasis following increased insulin resistance.

Autophagy has been reported to play a crucial role in the maintenance of intracellular homeostasis, including in pancreatic beta cells. Rubicon, which interacts with the phosphoinositide 3-kinase (PI3K) complex, through autophagy-related 14 (ATG14), is among the few autophagy regulators that have been reported to inhibit autophagic flux to date and the deletion of Rubicon has been shown to increase autophagic flux. Based on previous results showing a causal relationship between autophagic dysfunction and pancreatic beta-cell impairment, we hypothesized that the deletion of Rubicon in pancreatic beta cells would improve cell integrity and confer protective effects. To test this hypothesis, we first confirmed that Rubicon knockdown (KD) promoted autophagic flux in ßTC3 pancreatic beta-cell line. Next, we generated pancreatic beta-cell-specific Rubicon knockout (ßKO) mice, by administering tamoxifen to Rubiconflox/flox:MIP-Cre-ERT mice, which showed normal glucose tolerance and insulin secretion under a normal chow diet, despite successful gene recombination. We also attempted to increase insulin resistance by feeding the mice with a high-fat diet for an additional 2 months to find little differences among the parameters evaluated for glucose metabolism. Finally, severe insulin resistance was induced with insulin receptor antagonist treatment, which resulted in comparable glucose homeostasis measurements between Rubicon ßKO and control mice. In summary, these results suggest that in pancreatic beta cells, Rubicon plays a limited role in the maintenance of systemic glucose homeostasis.

Testicular rhabdomyosarcoma after chemotherapy for metastatic germ cell tumors.

A 36-year-old male was referred to our hospital with left scrotal swelling. Computed tomography revealed a massive tumor in his left scrotum. The tumor extended along the gonadal vein extraperitoneally forming a massive tumor. Pathological examination showed a mixed-type germ cell tumor. Despite several chemotherapeutic treatments, the tumor continued to grow, and the patient died 28 months later after his first presentation at our institution. Autopsy revealed that the tumor comprised rhabdomyosarcoma and mature teratoma. We could not find useful tumor markers to facilitate the diagnosis of rhabdomyosarcoma. However, we recommend rebiopsy or palliative operation as options for re-diagnosis in case of resistant germ cell tumor. Here, we present a case of testicular tumor that exhibited different pathological examination results before and after treatment.

Efficacy of combined prophylactic use of levofloxacin and isepamicin for transrectal prostate needle biopsy: A retrospective single-center study.

PURPOSE: To assess the efficacy of a combined regimen of levofloxacin (LVFX) plus isepamicin (ISP) as prophylaxis for transrectal ultrasound-guided needle biopsy of the prostate (TRUSP-Bx). MATERIALS AND METHODS: Overall, 562 patients undergoing TRUSP-Bx were included in the present study. All patients were administered a single-dose of oral LVFX (500 mg) in the morning and intravenous ISP (400 mg) 60 min before biopsy. All biopsies were performed via TRUSP-Bx with an 18-gauge needle, and 12-core specimens were routinely obtained. Before initiating antibiotic treatment, urine and blood bacterial cultures were tested to determine the causative microorganisms in the patients with acute bacterial prostatitis. RESULTS: Acute bacterial prostatitis developed in three (0.53%) participants. The incidence rates of acute bacterial prostatitis in the low- and high-risk groups were 0.79% and 0.46%, respectively. These patients showed clinical symptoms of acute bacterial prostatitis 12-24 h after their biopsy. Escherichia coli (E. coli) was isolated in the urine or bladder cultures of all of patients. All three isolates were determined to be LVFX-resistant E. coli, although they had good sensitivity to aminoglycosides, cephalosporins, and carbapenems. All patients were administered antibiotic treatment (cephalosporin or carbapenem) immediately and were treated successfully with no evidence of further disease progression. CONCLUSION: Antibiotic prophylaxis with LVFX plus ISP was effective, resulting in a lower incidence of acute bacterial prostatitis after TRUSP-Bx in both low- and high-risk patients.