ABSTRACT
Organic anion transporting polypeptide (OATP) 1B1 and OATP1B3 are important hepatic transporters. We previously identified OATP1B3 being critically implicated in the disposition of abiraterone. We aimed to further investigate the effects of abiraterone on the activities of OATP1B1 and OATP1B3 utilizing a validated endogenous biomarker coproporphyrin I (CP-I). We utilized OATP1B-transfected cells to characterize the inhibitory potential of abiraterone against OATP1B-mediated uptake of CP-I. Inhibition constant (Ki) was incorporated into our physiologically based pharmacokinetic (PBPK) modeling to simulate the systemic exposures of CP-I among cancer populations receiving either our model-informed 500 mg or clinically approved 1000 mg abiraterone acetate (AA) dosage. Simulated data were compared with clinical CP-I concentrations determined among our 9 metastatic prostate cancer patients receiving 500 mg AA treatment. Abiraterone inhibited OATP1B3- but not OATP1B1-mediated uptake of CP-I in vitro, with an estimated Ki of 3.93 µM. Baseline CP-I concentrations were simulated to be 0.81 {plus minus} 0.26 ng/mL, and determined to be 0.72 {plus minus} 0.16 ng/mL among metastatic prostate cancer patients, both of which were higher than those observed for healthy subjects. PBPK simulations revealed an absence of OATP1B3-mediated interaction between abiraterone and CP-I. Our clinical observations confirmed that CP-I concentrations remained comparable to baseline levels up to 12 weeks post 500 mg AA treatment. Using CP-I as an endogenous biomarker, we identified the inhibition of abiraterone on OATP1B3 but not OATP1B1 in vitro, which was predicted and observed to be clinically insignificant. We concluded that the interaction risk between AA and substrates of OATP1Bs is low. Significance Statement We utilized the endogenous biomarker coproporphyrin I (CP-I) and identified abiraterone as a moderate inhibitor of organic anion transporting polypeptide (OATP) 1B3 in vitro. Subsequent physiologically based pharmacokinetic (PBPK) simulations and clinical observations suggested an absence of OATP1B-mediated interaction between abiraterone and CP-I among prostate cancer patients. This multi-pronged study concluded that the interaction risk between abiraterone acetate and substrates of OATP1Bs is low, demonstrating the application of PBPK-CP-I modelling in predicting OATP1B-mediated interaction implicating abiraterone.
ABSTRACT
PURPOSE: We compare Prostate Health Index, Prostate Health Index density, and PSA density in predicting clinically significant prostate cancer in MRI-guided prostate biopsy. MATERIALS AND METHODS: This is a multicenter evaluation of prospectively maintained prostate biopsy databases at 10 urology centers. Men with Prostate Health Index and MRI-guided targeted and systematic prostate biopsy performed and without prior prostate cancer diagnosis were included. The additional value of PSA density, Prostate Health Index, and Prostate Health Index density to MRI PI-RADS (Prostate Imaging Reporting & Data System) score was evaluated with multivariable analyses, area under the curve, and decision curve analyses. The proportion of unnecessary biopsies that can be avoided are estimated for clinically significant prostate cancer (International Society of Urological Pathology group ≥2 prostate cancer). RESULTS: A total of 1,215 men were analyzed. Prostate cancer and clinically significant prostate cancer were diagnosed in 51% (617/1,215) and 35% (422/1,215) of men, respectively. Clinically significant prostate cancer was diagnosed in 4.4% (3/68), 15% (72/470), 39% (176/446), and 74% (171/231) of highest PI-RADS score of 2, 3, 4, and 5 lesions, respectively. In multivariable analyses, independent predictors for clinically significant prostate cancer detection included Prostate Health Index (OR 1.04), prostate volume (OR 0.97), and PI-RADS score 4 (OR 2.81) and 5 (OR 8.34). Area under the curve for clinically significant prostate cancer of PI-RADS + Prostate Health Index density (0.85) was superior to PI-RADS + PSA density (0.81), Prostate Health Index density (0.81), Prostate Health Index (0.78), PI-RADS (0.76), PSA density (0.72), and PSA (0.60) in the whole cohort, and the superiority of Prostate Health Index density was also observed in PI-RADS 3 lesions. Decision curve analysis showed Prostate Health Index density achieving the best net clinical benefit in PI-RADS 3 or 4 cases. Among PI-RADS 3 lesions, using cutoffs of PSA density 0.15, Prostate Health Index 38.0, and Prostate Health Index density 0.83 could reduce 58%, 67%, and 72% of unnecessary biopsies, respectively. CONCLUSIONS: Prostate Health Index density outperformed Prostate Health Index or PSA density in clinically significant prostate cancer detection in men with multiparametric MRI performed, and further reduced unnecessary biopsies in PI-RADS 3 lesions.
Subject(s)
Prostatic Neoplasms , Male , Humans , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Prostate/pathology , Prostate-Specific Antigen/analysis , Magnetic Resonance Imaging/methods , Retrospective Studies , Image-Guided Biopsy/methodsABSTRACT
BACKGROUND: Magnetic resonance imaging (MRI) scans are increasingly first-line investigations for suspected prostate cancer, and essential in the decision for biopsy. 5-alpha reductase inhibitor (5-ARI) use has been shown to reduce prostate size and prostate cancer risk. However, insufficient data exists on how 5-ARI use affects MRI findings and yield of biopsy. This study explores the differences in imaging and prostate cancer diagnoses between patients receiving and not receiving 5-ARI therapy. METHODS: From 2015 to 2020, we collected retrospective data of consecutive patients undergoing prostate biopsy at one centre. We included patients who were biopsy-naïve, had prior negative biopsies, or on active surveillance for low-grade prostate cancer. Clinical and pathological data was collected, including 5-ARI use, Prostate Imaging Reporting and Data System (PIRADS) classification and biopsy results. RESULTS: 351 men underwent saturation biopsy with or without targeted biopsies. 54 (15.3%) had a history of 5-ARI use. On mpMRI, there was no significant difference between the 5ARI and non-5-ARI groups in PIRADS distribution, number of lesions, and lesion location. Significantly fewer cancers were detected in the 5-ARI group (46.3% vs. 68.0%; p < 0.01). There were no significant differences in PIRADS distribution in 5-ARI patients with positive and negative biopsy. CONCLUSION: Our study found significant differences in biochemical, imaging and biopsy characteristics between 5-ARI and non-5-ARI groups. While both groups had similar PIRADS distribution, 5-ARI patients had a lower rate of positive biopsies across all PIRADS categories, which may suggest that the use of 5ARI may confound MRI findings. Further studies on how 5-ARI therapy affects the imaging characteristics of prostate cancer should be performed.
Subject(s)
Prostate , Prostatic Neoplasms , Male , Humans , Prostate/diagnostic imaging , Prostate/pathology , 5-alpha Reductase Inhibitors/therapeutic use , Retrospective Studies , Image-Guided Biopsy/methods , Prostatic Neoplasms/pathology , Magnetic Resonance Imaging/methodsABSTRACT
PURPOSE: To review the role of serum biomarkers: prostate-specific antigen (PSA), PSA density (PSAD), free:total PSA ratio, prostate health index (PHI) and PHI density (PHID), along with magnetic resonance imaging (MRI) for identification of clinically significant prostate cancer (PCa), comparing their utility in patients with persistently raised PSA levels after a prior negative prostate biopsy (PNB). METHODS: In this single-centre prospective observational study conducted from September 2015 to October 2020, patients underwent a saturation biopsy via the transperineal route. If a Prostate Imaging Reporting and Data System version 2 (PIRADS) 3 and above lesion was seen on MRI, targeted biopsies were also obtained. Information on clinical history, lesion characteristics, PIRADS classification and follow-up was collected. The sensitivity, specificity and area under curve (AUC) for each of the biomarkers were calculated. RESULTS: 351 men underwent saturation biopsy with or without targeted biopsies. 103 patients had a PNB. Among this PNB cohort, 43 (41.7%) men had a benign outcome, while 60 (58.3%) men had histopathologically diagnosed PCa, of which 41 (39%) were clinically significant. All patients underwent multiparametric MRI scans prior to biopsy. Within this cohort, PHI and PHID had the best abilities to predict for clinically significant PCa with an AUC of 0.73 and 0.70 respectively, compared to 0.65 for PSAD, 0.34 for free:total PSA and 0.56 for PSA. CONCLUSION: A significant proportion of patients are diagnosed with PCa after a PNB. This study shows that PHI and PHI densities may be suitable adjuncts predicting for clinically significant PCa in patients with PNB.
Subject(s)
Prostate , Prostatic Neoplasms , Biopsy , Humans , Image-Guided Biopsy , Magnetic Resonance Imaging , Male , Prostate/diagnostic imaging , Prostate/pathology , Prostate-Specific Antigen , Prostatic Neoplasms/pathologyABSTRACT
OBJECTIVES: To investigate plasma and urinary kynurenine (KYN)-tryptophan (TRP) ratios in bladder cancer, expression of indoleamine 2,3-dioxygenase 1 (IDO1) in relation to tryptophan 2,3-dioxygenase (TDO2) in bladder tumour, and the correlation of KYN-TRP ratio with bladder tumour burden. METHODS: Metabotyping of the TRP-KYN metabolic axis was performed via a clinical case-control study. Expression of IDO1 and TDO2 was measured in human biopsied tissues. Correlational experiments between KYN-TRP ratio and bladder tumour were performed using a murine orthotopic prostate-specific antigen (PSA)-secreting MB49 bladder cancer model. RESULTS: We established for the first time that plasma TRP level was significantly decreased, while both plasma and urinary KYN-TRP ratios were significantly higher in bladder cancer patients, and expression level of IDO1 but not TDO2 was increased in human bladder tumour. We reported the positive correlation between IDO1 expression, KYN-TRP ratio, normalized PSA to creatinine, and bladder tumour burden in the murine model. CONCLUSION: Kynurenine-tryptophan ratio is a promising surveillance biomarker for bladder cancer, but would require further validation before clinical translation.
Subject(s)
Biomarkers, Tumor/blood , Biomarkers, Tumor/urine , Kynurenine/blood , Kynurenine/urine , Tryptophan/blood , Tryptophan/urine , Urinary Bladder Neoplasms/blood , Urinary Bladder Neoplasms/urine , Aged , Case-Control Studies , Correlation of Data , Female , Humans , Male , Middle AgedABSTRACT
PURPOSE: The overall objective of the survey was to systematically examine patients' perspectives on lower urinary tract symptoms (LUTS) and their treatment in Southeast Asia. METHODS: A multinational cross-sectional survey involving adult men seeking consultation at urology outpatient clinics because of LUTS in Southeast Asia was conducted using convenience sampling. Self-reported prevalence, bother, treatment and treatment satisfaction of selected LUTS including urgency, nocturia, slow stream, and post-micturition dribble were evaluated. RESULTS: In total, 1535 eligible patients were enrolled in the survey. A majority of respondents were aged 56-75 years, not employed, and had not undergone prostate operation before. Overall, the self-reported prevalence of nocturia was 88% (95% CI 86-90%), slow stream 61% (95% CI 59-63%), post micturition dribble 55% (95% CI 52-58%), and urgency 52% (95% CI 49-55%). There were marked differences in the country specific prevalence of LUTS complaints. Frequently, symptoms coexisted and were combined with nocturia. More than half of patients felt at least some degree of bother from their symptoms: 61% for urgency, 57% for nocturia, 58% for slow stream, and 60% for post-micturition dribble. Before seeing the present urologists, nearly half of patients have received some form of prescribed treatment and more than 80% of patients indicated they would like to receive treatment. CONCLUSION: Men who sought urologist care for LUTS often presented with multiple symptoms. Nocturia emerged as the most common symptom amongst the four core symptoms studied.
Subject(s)
Lower Urinary Tract Symptoms , Adolescent , Adult , Aged , Cross-Sectional Studies , Diagnostic Self Evaluation , Humans , Lower Urinary Tract Symptoms/diagnosis , Lower Urinary Tract Symptoms/epidemiology , Lower Urinary Tract Symptoms/therapy , Male , Middle Aged , Patient Satisfaction , Prevalence , Young AdultABSTRACT
Objectives: To compare and review the outcomes of transperineal (TP) prostate biopsies with transrectal (TR) biopsies performed under local anaesthesia (LA). A review of the relevant published literature is presented. Patients and methods: We prospectively analysed 212 consecutive patients who underwent TP prostate biopsy using the PrecisionPoint™ access system under LA, at our institution from October 2018 to March 2020. We compared the morbidity and cancer detection rates using this approach with our historical cohort of 178 patients who underwent the TR biopsy method under LA. Results: The mean age of the TP biopsy group was 69 years, and median prostate specific antigen (PSA) was 13.17 ng/ml. Mean prostate volume was 45.1 ml with a median of 12 cores taken per patient. Patient demographics were similar to our TR biopsy cohort, with mean age of 68 years, median PSA of 10.76, mean prostate volume of 49.6 ml and a median of 12 cores taken per patient. The TP biopsy group had 0% sepsis rate compared with 2.2% in the TR group. Haematuria in the TP versus transrectal ultrasonography (TRUS) cohort was 0.9% versus 1.7%, respectively. The TP biopsy-naïve group had a cancer detection rate of 63.5% (127 of 200 patients), of which 84% were ≥Grade Group 2 (GG2). The TR biopsy-naïve group had cancer detection rate of 50% (86 of 172 patients), of which 87.2% was ≥GG2. Conclusion: TP prostate biopsy had less urinary infectious and septic complications compared with the TR approach. Our data suggest at least comparable diagnostic accuracy between both biopsy approaches.