A.N. Vis

Lower Testosterone Levels With Luteinizing Hormone-Releasing Hormone Agonist Therapy Than With Surgical Castration: New Insights Attained by Mass Spectrometry

PURPOSE Androgen deprivation therapy by bilateral orchiectomy (surgical castration) or luteinizing hormone-releasing hormone agonist therapy (medical castration) is recommended for advanced or metastatic prostate cancer. Both methods aim at reducing serum testosterone concentrations to a castrate level which is currently defined as less than 50 ng/dl. The results of previous studies are based on testosterone immunoassays that have insufficient accuracy in the low range. In this study we reevaluated serum testosterone concentrations in men on androgen deprivation therapy using isotope dilution-liquid chromatography-tandem mass spectrometry, an accurate method of measuring testosterone in the castrate range. MATERIALS AND METHODS Subjects underwent surgical castration (34) or received a luteinizing hormone-releasing hormone agonist (32). Serum samples were obtained more than 3 months after surgery or initiation of luteinizing hormone-releasing hormone agonist therapy. Testosterone levels were determined using isotope dilution-liquid chromatography-tandem mass spectrometry. Dihydroepiandrosterone sulfate, androstenedione, sex hormone-binding globulin and inhibin B levels were determined. RESULTS All subjects had serum testosterone values less than 50 ng/dl and 97% had testosterone concentrations less than 20 ng/dl. Medically castrated men had significantly lower testosterone levels (median 4.0 ng/dl, range less than 2.9 to 20.2) than those surgically castrated (median 9.2 ng/dl, range less than 2.9 to 28.8, p <0.001). No difference was found in dehydroepiandrosterone sulfate, androstenedione and sex hormone-binding globulin levels between the groups, whereas inhibin B levels were significantly higher in the luteinizing hormone-releasing hormone agonist treated group. CONCLUSIONS Using an accurate technique for testosterone measurement, subjects on luteinizing hormone-releasing hormone agonist therapy had significantly lower testosterone concentrations than men who underwent surgical castration. The clinical relevance of these findings remains to be determined.

Non‑invasive prostate cancer detection by measuring miRNA variants (isomiRs) in urine extracellular vesicles.

In many cancer types, the expression and function of ∼22 nucleotide-long microRNAs (miRNA) is deregulated. Mature miRNAs can be stably detected in extracellular vesicles (EVs) in biofluids, therefore they are considered to have great potential as biomarkers. In the present study, we investigated whether miRNAs have a distinct expression pattern in urine-EVs of prostate cancer (PCa) patients compared to control males. By next generation sequencing, we determined the miRNA expression in a discovery cohort of 4 control men and 9 PCa patients. miRNAs were validated by using a stemloop RT-PCR in an independent cohort of 74 patients (26 control and 48 PCa-patients). Whereas standard mapping protocols identified > 10 PCa associated miRNAs in urinary EVs, miR-21, miR-375 and miR-204 failed to robustly discriminate for disease in a validation study with RT-PCR-detection of mature miRNA sequences. In contrast, we observed that miRNA isoforms (isomiRs) with 3′ end modifications were highly discriminatory between samples from control men and PCa patients. Highly differentially expressed isomiRs of miR-21, miR-204 and miR-375 were subsequently validated in an independent group of 74 patients. Receiver-operating characteristic analysis was performed to evaluate the diagnostic performance of three isomiRs, resulting in a 72.9% sensitivity with a high (88%) specificity and an area under the curve (AUC) of 0.866. In comparison, prostate specific antigen had an AUC of 0.707 and measuring the mature form of these miRNAs yielded a lower 70.8% sensitivity and 72% specificity (AUC 0.766). We propose that isomiRs may carry discriminatory information which is useful to generate stronger biomarkers.

Feasibility of urinary extracellular vesicle proteome profiling using a robust and simple, clinically applicable isolation method

ABSTRACT Extracellular vesicles (EVs) secreted by prostate cancer (PCa) cells contain specific biomarkers and can be isolated from urine. Collection of urine is not invasive, and therefore urinary EVs represent a liquid biopsy for diagnostic and prognostic testing for PCa. In this study, we optimised urinary EV isolation using a method based on heat shock proteins and compared it to gold-standard ultracentrifugation. The urinary EV isolation protocol using the Vn96-peptide is easier, time convenient (≈1.5 h) and no special equipment is needed, in contrast to ultracentrifugation protocol (>3.5 h), making this protocol clinically feasible. We compared the isolated vesicles of both ultracentrifugation and Vn96-peptide by proteome profiling using mass spectrometry-based proteomics (n = 4 per method). We reached a depth of >3000 proteins, with 2400 proteins that were commonly detected in urinary EVs from different donors. We show a large overlap (>85%) between proteins identified in EVs isolated by ultracentrifugation and Vn96-peptide. Addition of the detergent NP40 to Vn96-peptide EV isolations reduced levels of background proteins and highly increased the levels of the EV-markers TSG101 and PDCD6IP, indicative of an increased EV yield. Thus, the Vn96-peptide-based EV isolation procedure is clinically feasibly and allows large-scale protein profiling of urinary EV biomarkers.

Effect on Survival of Androgen Deprivation Therapy Alone Compared to Androgen Deprivation Therapy Combined with Concurrent Radiation Therapy to the Prostate in Patients with Primary Bone Metastatic Prostate Cancer in a Prospective Randomised Clinical Trial: Data from the HORRAD Trial

BACKGROUND The cornerstone of standard treatment for patients with primary bone metastatic prostate cancer (mPCa) is androgen deprivation therapy (ADT). Retrospective studies suggest a survival benefit for treatment of the primary prostatic tumour in mPCa, but to date, no randomised-controlled-trials (RCTs) have been published addressing this issue. OBJECTIVE To determine whether overall survival is prolonged by adding local treatment of the primary prostatic tumour with external beam radiation therapy (EBRT) to ADT. DESIGN, SETTING, AND PARTICIPANTS The HORRAD trial is a multicentre RCT recruiting 432 patients with prostate-specific antigen (PSA) >20ng/ml and primary bone mPCa on bone scan between 2004 and 2014. INTERVENTION Patients were randomised to either ADT with EBRT (radiotherapy group) or ADT alone (control group). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Primary endpoint was overall survival. Secondary endpoint was time to PSA progression. Crude and adjusted analyses were applied to evaluate treatment effect. RESULTS AND LIMITATIONS Median PSA level was 142ng/ml and 67% of patients had more than five osseous metastases. Median follow up was 47 mo. Median overall survival was 45 mo (95% confidence interval [CI], 40.4-49.6) in the radiotherapy group and 43 mo (95% CI: 32.6-53.4) in the control group (p=0.4). No significant difference was found in overall survival (hazard ratio [HR]: 0.90; 95% CI: 0.70-1.14; p=0.4). Median time to PSA progression in the radiotherapy group was 15 mo (95% CI: 11.8-18.2), compared with 12 mo (95% CI: 10.6-13.4) in the control group. The crude HR (0.78; 95% CI: 0.63-0.97) was statistically significant (p=0.02). CONCLUSIONS The current RCT comparing ADT to ADT with EBRT to the prostate in patients with primary bone mPCa did not show a significant difference in overall survival, although the CI cannot exclude a substantial survival benefit. Further research is needed to confirm our findings. PATIENT SUMMARY This study investigated the effect of adding radiation therapy to the prostate to hormonal therapy in prostate cancer patients with metastasis to the bone at diagnosis. In our patient group, additional radiotherapy did not improve overall survival. Further research is needed to confirm our findings. TWITTER SUMMARY Adding radiotherapy to the prostate in patients with bone metastatic prostate cancer does not improve overall survival.

Robot-assisted Laparoscopic Implantation of Brachytherapy Catheters in Bladder Cancer

BACKGROUND Robot-assisted laparoscopic (RAL) implantation of brachytherapy catheters (BTCs) can be a minimally invasive alternative to open retropubic implantation. Descriptions of the surgical technique and outcomes are sparse. OBJECTIVE To describe our technique and perioperative outcomes for RAL BTC implantation in urothelial carcinoma (UC) and urachal carcinoma (UraC). DESIGN, SETTING AND PARTICIPANTS Between June 2011 and May 2016, 26 patients with cN0M0 solitary T1G3 or T2G1-3 UC of ≤5cm or cN0M0 UraC were scheduled for external beam radiotherapy (20×2Gy), RAL BTC implantation, and pulsed-dose (29×1.04Gy) or high-dose rate brachytherapy (10×2.50Gy). Median follow-up was 12 mo (interquartile range 4-20). SURGICAL PROCEDURE RAL BTC implantation with or without pelvic lymph node dissection and/or partial cystectomy. MEASUREMENTS AND STATISTICAL ANALYSIS Perioperative data, complications, disease-free-survival (DFS), local recurrence-free survival (LRFS), and cystectomy-free survival (CFS) were evaluated as well as the feasibility of the technique. RESULTS AND LIMITATIONS BTC implantation was successful in 92% of the patients. Median hospitalisation was 5 d (interquartile range 4-7) and blood loss <50ml in all cases. DFS was 74% at 1 yr and 63% at 2 yr. LRFS was 80% at 1 and 2 yr, and CFS was 87% at 1 and 2 yr. Early (≤30 d) high-grade complications (Clavien-Dindo ≥3) occurred in 8% of the patients. The study is limited by the small sample size and short follow-up time. CONCLUSIONS RAL BTC implantation is technically feasible and could serve as safe, minimally invasive alternative to open surgery in selected patients. The results of this study should be confirmed in larger studies. PATIENT SUMMARY Brachytherapy catheter (BTC) implantation is traditionally carried out via open retropubic surgery. We describe robot-assisted laparoscopic BTC implantation as a minimally invasive alternative. Perioperative outcomes are described and confirm the safety and feasibility of this procedure.

23 De correlatie van histologische beoordeling van prostaatbiopten tussen verwijzend patholoog en uropatholoog

SamenvattingEr bestaat interindividuele variatie bij de histologische beoordeling van prostaatbiopten.