Interassay Variability and Clinical Implications of Five Different Prostate-specific Antigen Assays.

Background and objective: Prostate-specific antigen (PSA) remains a critical marker for prostate cancer (PCa) detection and monitoring. Recognising historical variability in PSA assays and the evolution of assay technology and calibration, this study aims to reassess interassay variability using the latest generation of five assays in a contemporary cohort of men undergoing prostate biopsy. Methods: Five different commercially available PSA assays were tested in a blood sample of 76 men before undergoing a prostate biopsy. Total PSA (tPSA) and free-to-total PSA ratio (%fPSA) were compared across assays, using Roche (Basel, Switzerland) as the benchmark, and correlated with biopsy outcome to analyse the impact on PCa diagnosis. The statistical analysis included Passing-Bablok regression and Bland-Altman plots, with a p value threshold of <0.05 for significance. Key findings and limitations: Among the 76 men, 28 (36.8%) were diagnosed with significant PCa (defined as International Society of Urological Pathology grade ≥2). A high correlation was observed between tPSA and %fPSA values among the different PSA assays tested (r2 ≥ 0.9). The Passing-Bablok analysis showed that tPSA results varied substantially among the assays, with slopes ranging between 0.78 and 1.04. Compared with the tPSA of Roche, tPSA values were on average 20.7% lower by Beckman (Oststeinbeck, Germany), 15.2% lower by Abbott (Chicago, IL, USA), 6.1% lower by Diasorin (Saluggia, Italy), and 9.6% higher by Brahms (Hennigsdorf, Germany; p < 0.001 for all). The %fPSA values by Abbott and Brahms were higher at 15.7% and 10.6%, respectively (p < 0.001), while the Beckman and Diasorin values had minimal differences of -0.3% and 2.3%, respectively (p > 0.05). The variability across assays would have resulted in discrepancies in both the sensitivity and the specificity for tPSA and %fPSA by at least 14%, depending on the cut-offs applied. Conclusions and clinical implications: Despite the use of the latest PSA assays, relevant variability of tPSA and %fPSA results can be observed among different assays. There is an urgent need for standardised calibration methods and greater awareness among practitioners concerning interassay variability. Clinicians should acknowledge that clinically relevant thresholds may depend on the specific PSA assay and that ideally the same assay is applied over time for better clinical decision-making. Patient summary: Prostate-specific antigen (PSA) is a critical marker for prostate cancer (PCa) detection and monitoring. However, significant variations were observed in the results of the latest PSA assays. Thus, standardised calibration methods and greater awareness among practitioners concerning interassay variability are needed.

BioPrev-C - development and validation of a contemporary prostate cancer risk calculator.

Objectives: To develop a novel biopsy prostate cancer (PCa) prevention calculator (BioPrev-C) using data from a prospective cohort all undergoing mpMRI targeted and transperineal template saturation biopsy. Materials and methods: Data of all men who underwent prostate biopsy in our academic tertiary care center between 11/2016 and 10/2019 was prospectively collected. We developed a clinical prediction model for the detection of high-grade PCa (Gleason score ≥7) based on a multivariable logistic regression model incorporating age, PSA, prostate volume, digital rectal examination, family history, previous negative biopsy, 5-alpha-reductase inhibitor use and MRI PI-RADS score. BioPrev-C performance was externally validated in another prospective Swiss cohort and compared with two other PCa risk-calculators (SWOP-RC and PBCG-RC). Results: Of 391 men in the development cohort, 157 (40.2%) were diagnosed with high-grade PCa. Validation of the BioPrev C revealed good discrimination with an area under the curve for high-grade PCa of 0.88 (95% Confidence Interval 0.82-0.93), which was higher compared to the other two risk calculators (0.71 for PBCG and 0.84 for SWOP). The BioPrev-C revealed good calibration in the low-risk range (0 - 0.25) and moderate overestimation in the intermediate risk range (0.25 - 0.75). The PBCG-RC showed good calibration and the SWOP-RC constant underestimation of high-grade PCa over the whole prediction range. Decision curve analyses revealed a clinical net benefit for the BioPrev-C at a clinical meaningful threshold probability range (≥4%), whereas PBCG and SWOP calculators only showed clinical net benefit above a 30% threshold probability. Conclusion: BiopPrev-C is a novel contemporary risk calculator for the prediction of high-grade PCa. External validation of the BioPrev-C revealed relevant clinical benefit, which was superior compared to other well-known risk calculators. The BioPrev-C has the potential to significantly and safely reduce the number of men who should undergo a prostate biopsy.

Safety and quality of cystectomy and pelvic lymph node dissection after neoadjuvant durvalumab and cisplatin/gemcitabine.

OBJECTIVE: To report on the surgical safety and quality of pelvic lymph node dissection (PLND) in patients treated with radical cystectomy (RC) and PLND for muscle-invasive bladder cancer (MIBC) after neoadjuvant chemo-immunotherapy. PATIENTS AND METHODS: The Swiss Group for Clinical Cancer Research (SAKK) 06/17 was an open-label single-arm phase II trial including 61 cisplatin-fit patients with clinical stage (c)T2-T4a cN0-1 operable urothelial MIBC or upper urinary tract cancer. Patients received neoadjuvant cisplatin/gemcitabine and durvalumab followed by surgery. Prospective quality assessment of surgeries was performed via central review of intraoperative photographs. Postoperative complications were assessed using the Clavien-Dindo Classification. Data were analysed descriptively. RESULTS: A total of 50 patients received RC and PLND. All patients received neoadjuvant chemo-immunotherapy. The median (interquartile range) number of lymph nodes removed was 29 (23-38). No intraoperative complications were registered. Grade ≥III postoperative complications were reported in 12 patients (24%). Complete nodal dissection (100%) was performed at the level of the obturator fossa (bilaterally) and of the left external iliac region; in 49 patients (98%) at the internal iliac region and at the right external iliac region; in 39 (78%) and 38 (76%) patients at the right and left presacral level, respectively. CONCLUSION: This study supports the surgical safety of RC and PLND following neoadjuvant chemo-immunotherapy in patients with MIBC. The extent and completeness of protocol-defined PLND varies between patients, highlighting the need to communicate and monitor the surgical template.

Interdisciplinary Swiss consensus recommendations on staging and treatment of advanced prostate cancer.

The management of prostate cancer is undergoing rapid changes in all disease settings. Novel imaging tools for diagnosis have been introduced, and the treatment of high-risk localized, locally advanced and metastatic disease has changed considerably in recent years. From clinical and health-economic perspectives, a rational and optimal use of the available options is of the utmost importance. While international guidelines list relevant pivotal trials and give recommendations for a variety of clinical scenarios, there is much room for interpretation, and several important questions remain highly debated. The goal of developing a national consensus on the use of these novel diagnostic and therapeutic strategies in order to improve disease management and eventually patient outcomes has prompted a Swiss consensus meeting. Experts from several specialties, including urology, medical oncology, radiation oncology, pathology and nuclear medicine, discussed and voted on questions of the current most important areas of uncertainty, including the staging and treatment of high-risk localized disease, treatment of metastatic hormone-sensitive prostate cancer (mHSPC) and use of new options to treat metastatic castration-resistant prostate cancer (mCRPC).

Effectiveness of Flexible Ureterorenoscopy Versus Extracorporeal Shock Wave Lithotripsy for Renal Calculi of 5-15 mm: Results of a Randomized Controlled Trial.

BACKGROUND: Primary flexible ureterorenoscopy (URS) and extracorporeal shock wave lithotripsy (SWL) are treatment options in patients with renal calculi of 5-15 mm. OBJECTIVE: To compare effectiveness, complication rates, and pain scores between primary URS and SWL. DESIGN SETTING AND PARTICIPANTS: Between 2011 and 2016, patients with renal calculi between 5 and 15 mm were randomized to undergo either primary URS or SWL. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Stone-free rate and size of residual fragments assessed by computed tomography after 3 mo, complications, and pain scores were evaluated. RESULTS AND LIMITATIONS: The study was prematurely closed after randomizing 44 patients due to poor accrual. The 3-mo stone-free rate and mean residual stone size were, respectively, 61% and 1.8 mm after URS and 48% and 2.4 mm after SWL. Early post-treatment pain scores were significantly higher after URS than after SWL on day 1 (3.3 vs 1.6, p = 0.02) and day 7 (5.2 vs 3.4, p = 0.04), but were no longer detectable after 3 wk and 3 mo, respectively. One Clavien-Dindo grade II complication was observed after URS (5%) and SWL (4%), while one (4%) grade IIIb complication was observed after SWL. CONCLUSIONS: URS appears to be associated with higher early post-treatment discomfort, which could be associated with routine postoperative stenting. Owing to premature closure of this trial, the power was insufficient to formally compare URS and SWL; however, the present data might be informative to counsel patients about treatment outcomes and allow future meta-analyses. PATIENT SUMMARY: This study was ended prematurely, but it contributes data about efficacy and side effects of different treatment options in patients with renal calculi.

[Urinary stone disease - size isn't all that matters]. / Urolithiasis.

Urinary stone disease - size isn't all that matters Abstract. Urinary stone disease is a very frequent disease with a life-time-risk of about 10 - 15 % in industrialized countries. Meanwhile mostly asymptomatic stone formation takes place within the renal pelvic system (renal stone disease), the typical clinical manifestation results when these stones enter and consequently obstruct the ureter (ureteral stone disease). Hence, in case of acute flank pain, ureteral stone disease is one of the most important differential diagnosis and requires always an immediate as well as accurate diagnostic work up. In here, CT-scans have shown to be most accurate and outperform ultrasound, especially concerning the overall assessment of the stone situation in the patient. Beside the diagnosis of the stone disease, the medical history, vital signs as well as blood and urinary tests are of importance in the primary work up of the patient since the identification of a potential concurrent infection within the urinary tract is of highest importance. Both, renal stone disease (mostly asymptomatic) as well as ureteral stone disease (often associated with acute and destructive flank pain) are usually not associated with an immediate threat. Ureteral stone disease with a concurrent urinary tract infection in contrary is one of the most dangerous situations in urology and, if missed, associated with urosepsis and high morbidity even lethality. The immediate drainage of the obstructed and infected urinary tract is the most important emergency action in these patients.

Long-term oncological and functional follow-up in low-dose-rate brachytherapy for prostate cancer: results from the prospective nationwide Swiss registry.

OBJECTIVE: To evaluate the long-term oncological, functional and toxicity outcomes of low-dose-rate brachytherapy (LDR-BT) in relation to risk factors and radiation dose in a prospective multicentre cohort. PATIENTS AND METHODS: Data of patients from 12 Swiss centres undergoing LDR-BT from September 2004 to March 2018 were prospectively collected. Patients with a follow-up of ≥3 months were analysed. Functional and oncological outcomes were assessed at ~6 weeks, 6 and 12 months after implantation and annually thereafter. LDR-BT was performed with 125 I seeds. Dosimetry was done 6 weeks after implantation based on the European Society for Radiotherapy and Oncology recommendations. The Kaplan-Meier method was used for biochemical recurrence-free survival (BRFS). A prostate-specific antigen (PSA) rise above the PSA nadir + 2 was defined as biochemical failure. Functional outcomes were assessed by urodynamic measurement parameters and questionnaires. RESULTS: Of 1580 patients in the database, 1291 (81.7%) were evaluable for therapy outcome. The median (range) follow-up was 37.1 (3.0-141.6) months. Better BRFS was found for Gleason score ≤3+4 (P = 0.03, log-rank test) and initial PSA level of <10 ng/mL (P < 0.001). D'Amico Risk groups were significantly associated with BRFS (P < 0.001), with a hazard ratio of 2.38 for intermediate- and high-risk patients vs low-risk patients. The radiation dose covering 90% of the prostate volume (D90) after 6 weeks was significantly lower in patients with recurrence. Functional outcomes returned close to baseline levels after 2-3 years. A major limitation of these findings is a substantial loss to follow-up. CONCLUSION: Our results are in line with other studies showing that LDR-BT is associated with good oncological outcomes together with good functional results.

Erratum: Extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in the treatment of untreated renal calculi.

[This corrects the article DOI: 10.1093/ckj/sfx151.].

Extracorporeal shock wave lithotripsy versus flexible ureterorenoscopy in the treatment of untreated renal calculi.

BACKGROUND: The reported success rates for treatments of kidney stones with either extracorporeal shock wave lithotripsy (ESWL) or flexible ureterorenoscopy (URS) are conflicting. We aimed to compare the efficacy and safety of ESWL and URS for previously untreated renal calculi. METHODS: All patients treated with ESWL or URS at our tertiary care centre between 2003 and 2015 were retrospectively identified. Patients with previously untreated kidney stones and a stone diameter of 5-20 mm were included. Stone-free, freedom from reintervention and complication rates were recorded. Independent predictors of stone-free and freedom from reintervention rates were identified by multivariable logistic regression and a propensity score-matched analysis was performed. RESULTS: A total of 1282 patients met the inclusion criteria, of whom 999 (78%) underwent ESWL and 283 (22%) had URS. During post-operative follow-up, only treatment modality and stone size could independently predict stone-free and freedom from reintervention rates. After propensity score matching, ESWL showed significantly lower stone-free rates [ESWL (71%) versus URS (84%)] and fewer patients with freedom from reintervention [ESWL (55%) versus URS (79%)] than URS. Complications were scarce for both treatments and included Clavien Grade 3a in 0.8% versus 0% and Grade 3b in 0.5% versus 0.4% of ESWL and URS treated patients, respectively. CONCLUSIONS: Treatment success was mainly dependent on stone size and treatment modality. URS might be the better treatment option for previously untreated kidney stones 5-20 mm, with similar morbidity but higher stone-free rates and fewer reinterventions than ESWL.

Prevalence and causes of abnormal PSA recovery.

BACKGROUND: Prostate-specific antigen (PSA) test is of paramount importance as a diagnostic tool for the detection and monitoring of patients with prostate cancer. In the presence of interfering factors such as heterophilic antibodies or anti-PSA antibodies the PSA test can yield significantly falsified results. The prevalence of these factors is unknown. METHODS: We determined the recovery of PSA concentrations diluting patient samples with a standard serum of known PSA concentration. Based on the frequency distribution of recoveries in a pre-study on 268 samples, samples with recoveries <80% or >120% were defined as suspect, re-tested and further characterized to identify the cause of interference. RESULTS: A total of 1158 consecutive serum samples were analyzed. Four samples (0.3%) showed reproducibly disturbed recoveries of 10%, 68%, 166% and 4441%. In three samples heterophilic antibodies were identified as the probable cause, in the fourth anti-PSA-autoantibodies. The very low recovery caused by the latter interference was confirmed in serum, as well as heparin- and EDTA plasma of blood samples obtained 6 months later. Analysis by eight different immunoassays showed recoveries ranging between <10% and 80%. In a follow-up study of 212 random plasma samples we found seven samples with autoantibodies against PSA which however did not show any disturbed PSA recovery. CONCLUSIONS: About 0.3% of PSA determinations by the electrochemiluminescence assay (ECLIA) of Roche diagnostics are disturbed by heterophilic or anti-PSA autoantibodies. Although they are rare, these interferences can cause relevant misinterpretations of a PSA test result.

Oxygen supply maps for hypoxic microenvironment visualization in prostate cancer.

BACKGROUND: Intratumoral hypoxia plays an important role with regard to tumor biology and susceptibility to radio- and chemotherapy. For further investigation of hypoxia-related changes, areas of certain hypoxia must be reliably detected within cancer tissues. Pimonidazole, a 2-nitroimindazole, accumulates in hypoxic tissue and can be easily visualized using immunohistochemistry. MATERIALS AND METHODS: To improve detection of highly hypoxic versus normoxic areas in prostate cancer, immunoreactivity of pimonidazole and a combination of known hypoxia-related proteins was used to create computational oxygen supply maps of prostate cancer. Pimonidazole was intravenously administered before radical prostatectomy in n = 15 patients, using the da Vinci robot-assisted surgical system. Prostatectomy specimens were immediately transferred into buffered formaldehyde, fixed overnight, and completely embedded in paraffin. Pimonidazole accumulation and hypoxia-related protein expression were visualized by immunohistochemistry. Oxygen supply maps were created using the normalized information from pimonidazole and hypoxia-related proteins. RESULTS: Based on pimonidazole staining and other hypoxia.related proteins (osteopontin, hypoxia-inducible factor 1-alpha, and glucose transporter member 1) oxygen supply maps in prostate cancer were created. Overall, oxygen supply maps consisting of information from all hypoxia-related proteins showed high correlation and mutual information to the golden standard of pimonidazole. Here, we describe an improved computer-based ex vivo model for an accurate detection of oxygen supply in human prostate cancer tissue. CONCLUSIONS: This platform can be used for precise colocalization of novel candidate hypoxia-related proteins in a representative number of prostate cancer cases, and improve issues of single marker correlations. Furthermore, this study provides a source for further in situ tests and biochemical investigations.

Influence of Varying Assessment Parameters on the Diagnostic Accuracy of Magnetic Resonance Imaging in the Local Staging of Prostate Cancer.

INTRODUCTION: There is a broad variability in the accuracy levels of MRI with regard to the local staging of prostate cancer (PCa). METHODS: A prospective analysis was conducted in patients with localized PCa with MRI of the prostate before radical prostatectomy. MRI and pathology findings were independently reviewed and reported based on a standardized map of the prostate with 16 regions of interest (ROIs). Diagnostic accuracy analysis of the MRI was performed using varying prostate-subpart sizes and varying cutoffs for the radiological probability for PCa presence. RESULTS: Seventy four patients were included. Using varying cutoff probabilities and varying sizes of prostate-subparts resulted in a broad range of sensitivity (6-88%) and specificity (38-100%). Lower probabilities of PCa presence and larger prostate-subparts resulted in higher sensitivity but lower specificity and vice versa. Best diagnostic performance was achieved by using prostate sextants and at least moderate probabilities for PCa presence; mean sensitivity and specificity were 38% (95% CI 13-75) and 95% (95% CI 88-98). CONCLUSION: The use of varying assessment parameters strongly affects the diagnostic accuracy of MRI in the local staging of PCa. Hence, precise and standardized reporting regarding these parameters is important. In our study, using at least moderate probabilities for PCa presence on MRI and prostatic sextants as ROI size was associated with best diagnostic performance.

Bilaterally positive biopsy cores are associated with non-organ-confined disease in prostate cancer patients eligible for active surveillance.

PURPOSE: To investigate the association between the laterality of diagnostic prostate cancer-positive biopsy cores and definitive tumor stage on final pathology (organ-confined versus non-organ-confined). PATIENTS AND METHODS: This is a retrospective analysis of 165 men after radical prostatectomy fulfilling our active surveillance criteria at the time of surgery. Nominal variables were compared using Fisher's exact test, continuous variables using Mann-Whitney test. Odds ratios including 95% Wald and probabilities including 95% Wilson confidence intervals are provided. RESULTS: 5 (3%) patients had non-organ-confined disease: 2 out of 144 (1%) patients with unilateral and 3 out of 17 (18%) patients with bilateral cancer-positive biopsy cores (p = 0.009). The estimated odds ratio for non-organ-confined disease was 14.67 (95% confidence interval 1.55-189.23) for patients with bilateral compared to patients with unilateral cancer-positive biopsy cores. The sensitivity, specificity and accuracy of bilaterally positive biopsies as an additional criterion to identify non-organ-confined disease are 60, 91 and 90%, respectively. CONCLUSION: In our cohort, patients with bilaterally positive biopsy cores were significantly more likely to harbor a non-organ-confined tumor than patients with unilaterally positive cores. Due to their high specificity, bilaterally positive biopsies may represent a reasonable exclusion criterion for active surveillance if our results are corroborated in further studies.

Ablative efficiency of 532-nm laser vaporization compared to transurethral resection of the prostate: results from a prospective three-dimensional ultrasound volumetry study.

PURPOSE: To assess and compare postoperative prostate volume changes following 532-nm laser vaporization (LV) and transurethral resection of the prostate (TURP). To investigate whether differences in volume reduction are associated with differences in clinical outcome. METHODS: In this prospective, non-randomized study, 184 consecutive patients undergoing 120 W LV (n = 98) or TURP (n = 86) were included. Transrectal three-dimensional ultrasound and planimetric volumetry of the prostate were performed preoperatively, after catheter removal, 6 weeks, 6 and 12 months. Additionally, clinical outcome parameters were recorded. Mann-Whitney U test and analysis of covariance were utilized for statistical analysis. RESULTS: Postoperatively, a significant prostate volume reduction was detectable in both groups. However, the relative volume reduction was lower following LV (18.4 vs. 34.7 %, p < 0.001). After 6 weeks, prostate volumes continued to decrease in both groups, yet differences between the groups were less pronounced. Nonetheless, the relative volume reduction remained significantly lower following LV (12 months 43.3 vs. 50.3 %, p < 0.001). All clinical outcome parameters improved significantly in both groups. However, the maximum flow rate (Q max) and prostate-specific antigen (PSA) reduction were significantly lower following LV. Subgroup analyses revealed significant differences only if the initial prostate volume was >40 ml. Re-operations were necessary in three patients following LV. CONCLUSIONS: The modest but significantly lower volume reduction following LV was associated with a lower PSA reduction, a lower Q max and more re-operations. Given the lack of long-term results after LV, our results are helpful for preoperative patient counseling. Patients with large prostates and no clear indication for the laser might not benefit from the procedure.

Daily Pomegranate Intake Has No Impact on PSA Levels in Patients with Advanced Prostate Cancer - Results of a Phase IIb Randomized Controlled Trial.

Pomegranate has been shown to prolong PSA doubling time in early prostate cancer, but no data from a placebo controlled trial has been published yet. The objective of this study was to prospectively evaluate the impact of pomegranate juice in patients with prostate cancer. We conducted a phase IIb, double blinded, randomized placebo controlled trial in patients with histologically confirmed prostate cancer. Only patients with a PSA value ≥ 5ng/ml were included. The subjects consumed 500 ml of pomegranate juice or 500 ml of placebo beverage every day for a 4 week period. Thereafter, all patients received 250 ml of the pomegranate juice daily for another 4 weeks. PSA values were taken at baseline, day 14, 28 and on day 56. The primary endpoint was the detection of a significant difference in PSA serum levels between the groups after one month of treatment. Pain scores and adherence to intervention were recorded using patient diaries. 102 patients were enrolled. The majority of patients had castration resistant prostate cancer (68%). 98 received either pomegranate juice or placebo between October 2008 and May 2011. Adherence to protocol was good, with 94 patients (96%) completing the first period and 87 patients (89%) completing both periods. No grade 3 or higher toxicities occurred within the study. No differences were detected between the two groups with regard to PSA kinetics and pain scores. Consumption of pomegranate juice as an adjunct intervention in men with advanced prostate cancer does not result in significant PSA declines compared to placebo.

The role of 11C-choline and 18F-fluorocholine positron emission tomography (PET) and PET/CT in prostate cancer: a systematic review and meta-analysis.

CONTEXT: The role of positron emission tomography (PET) and PET/computed tomography (PET/CT) in prostate cancer (PCa) imaging is still debated, although guidelines for their use have emerged over the last few years. OBJECTIVE: To systematically review and conduct a meta-analysis of the available evidence of PET and PET/CT using 11C-choline and 18F-fluorocholine as tracers in imaging PCa patients in staging and restaging settings. EVIDENCE ACQUISITION: PubMed, Embase, and Web of Science (by citation of reference) were searched. Reference lists of review articles and included articles were checked to complement electronic searches. EVIDENCE SYNTHESIS: In staging patients with proven but untreated PCa, the results of the meta-analysis on a per-patient basis (10 studies, n = 637) showed pooled sensitivity, specificity, and diagnostic odds ratio (DOR) of 84% (95% confidence interval [CI], 68-93%), 79% (95% CI, 53-93%), and 20.4 (95% CI, 9.9-42.0), respectively. The positive and negative likelihood ratios were 4.02 (95% CI, 1.73-9.31) and 0.20 (95% CI, 0.11-0.37), respectively. On a per-lesion basis (11 studies, n = 5117), these values were 66% (95% CI, 56-75%), 92% (95% CI, 78-97%), and 22.7 (95% CI, 8.9-58.0), respectively, for pooled sensitivity, specificity, and DOR; and 8.29 (95% CI, 3.05-22.54) and 0.36 (95% CI, 0.29-0.46), respectively, for positive and negative likelihood ratios. In restaging patients with biochemical failure after local treatment with curative intent, the meta-analysis results on a per-patient basis (12 studies, n = 1055) showed pooled sensitivity, specificity, and DOR of 85% (95% CI, 79-89%), 88% (95% CI, 73-95%), and 41.4 (95% CI, 19.7-86.8), respectively; the positive and negative likelihood ratios were 7.06 (95% CI, 3.06-16.27) and 0.17 (95% CI, 0.13-0.22), respectively. CONCLUSIONS: PET and PET/CT imaging with 11C-choline and 18F-fluorocholine in restaging of patients with biochemical failure after local treatment for PCa might help guide further treatment decisions. In staging of patients with proven but untreated, high-risk PCa, there is limited but promising evidence warranting further studies. However, the current evidence shows crucial limitations in terms of its applicability in common clinical scenarios.

Multidrug resistance protein 4 (MRP4) expression in prostate cancer is associated with androgen signaling and decreases with tumor progression.

Multidrug resistance protein 4 (MRP4) is a transmembrane transport protein found in many cell types and is involved in substrate-specific transport of endogenous and exogenous substrates. Recently, it has shown to be expressed in prostate cancer cell lines and to be among the most commonly upregulated transcripts in prostate cancer, although a comprehensive expression analysis is lacking so far. We aimed to investigate its expression by immunohistochemistry in a larger cohort of neoplastic and nonneoplastic prostate tissues (n = 441) and to correlate its expression with clinicopathological parameters including PSA-free survival times and molecular correlates of androgen signaling (androgen receptor (AR), prostate-specific antigen (PSA), and forkhead box A (FoxA)). MRP4 is widely expressed in benign and neoplastic prostate epithelia, but its expression gradually decreases during tumor progression towards castrate-resistant disease. Concordantly, it correlated with conventional prognosticators of disease progression and-within the group of androgen-dependent tumors-with AR and FoxA expression. Moreover, lower levels of MRP4 expression were associated with shorter PSA relapse-free survival times in the androgen-dependent group. In benign tissues, we found zone-dependent differences of MRP4 expression, with the highest levels in the peripheral and central zones. Although MRP4 is known to be regulated in prostate cancer, this study is the first to demonstrate a gradual downregulation of MRP4 protein during malignant tumor progression and a prognostic value of this loss of expression.

FOXA1 promotes tumor progression in prostate cancer and represents a novel hallmark of castration-resistant prostate cancer.

Forkhead box protein A1 (FOXA1) modulates the transactivation of steroid hormone receptors and thus may influence tumor growth and hormone responsiveness in prostate cancer. We therefore investigated the correlation of FOXA1 expression with clinical parameters, prostate-specific antigen (PSA) relapse-free survival, and hormone receptor expression in a large cohort of prostate cancer patients at different disease stages. FOXA1 expression did not differ significantly between benign glands from the peripheral zone and primary peripheral zone prostate carcinomas. However, FOXA1 was overexpressed in metastases and particularly in castration-resistant cases, but was expressed at lower levels in both normal and neoplastic transitional zone tissues. FOXA1 levels correlated with higher pT stages and Gleason scores, as well as with androgen (AR) and estrogen receptor expression. Moreover, FOXA1 overexpression was associated with faster biochemical disease progression, which was pronounced in patients with low AR levels. Finally, siRNA-based knockdown of FOXA1 induced decreased cell proliferation and migration. Moreover, in vitro tumorigenicity was inducible by ARs only in the presence of FOXA1, substantiating a functional cooperation between FOXA1 and AR. In conclusion, FOXA1 expression is associated with tumor progression, dedifferentiation of prostate cancer cells, and poorer prognosis, as well as with cellular proliferation and migration and with AR signaling. These findings suggest FOXA1 overexpression as a novel mechanism inducing castration resistance in prostate cancer.

Profiling gastrin-releasing peptide receptor in prostate tissues: clinical implications and molecular correlates.

BACKGROUND: The gastrin-releasing peptide receptor (GRPR) has emerged as an attractive target for both therapeutic and diagnostic appliances, but has only insufficiently been characterized in the human prostate so far. The aim of this study is to profile GRPR in a large cohort and correlate it with clinicopathologic and molecular parameters. METHODS: Benign and malignant (primary carcinoma, metastases, and castration-resistant prostate cancer) prostate samples from 530 patients were analyzed immunohistochemically for GRPR, androgen receptor and Cyclin D1 expression. Staining intensity was assessed assigning a semiquantitative score to each sample. RESULTS: Normal prostate tissues were mostly GRPR negative, significantly higher expression rates were seen in primary carcinomas and metastases. Significant inverse correlations were found for GRPR and increasing Gleason score, PSA value, and tumor size. A stratified Kaplan-Meyer analysis for GRPR and high AR expression shows a significant prognostic advantage for high GRPR expression, whereas GRPR expression alone shows no independent prognostic value. Highly significant correlations for GRPR, AR, and Cyclin D1 were found. CONCLUSIONS: Our data show that GRPR is overexpressed in prostate cancer, particularly of lower grade and smaller size. These findings constitute a caveat for the use of GRPR as a target for diagnostic or therapeutic approaches to high grade or progressed prostate cancer.