R. Jeroen A. van Moorselaar

Exosomal ITGA3 interferes with non-cancerous prostate cell functions and is increased in urine exosomes of metastatic prostate cancer patients

Background Cancer cells are able to change the protein expression and behavior of non-cancerous surrounding cells. Exosomes, secreted by prostate cancer (PCa) cells, may have a functional role in cancer metastasis and present a promising source for protein biomarkers. The aim of the present study was to identify which proteins in exosomes can influence non-cancerous cells, and to determine whether we can use urine exosomal proteins to identify high-risk PCa patients. Method Exosomes were isolated by ultracentrifugation. Migration and invasion were studied by the transwell (invasion) assay. Proteomics was performed by LC-MS/MS and identified proteins were validated by Western blotting. Cellular uptake of fluorescent labeled PKH67-exosomes was measured by FACS. Results Based on comparative protein profiling by mass spectrometry-based proteomics of LNCaP- and PC3-exosomes, we selected ITGA3 and ITGB1, involved in migration/invasion, for further analyses. Inhibition of exosomal ITGA3 reduced the migration and invasion of non-cancerous prostate epithelial cells (prEC) almost completely. Cellular uptake of exosomes by prEC was higher with PC3-exosomes compared to LNCaP exosomes. Finally, ITGA3 and ITGB1 were more abundant in urine exosomes of metastatic patients (p<0.05), compared to benign prostate hyperplasia or PCa. Conclusion These data indicate exosomal ITGA3 and ITGB1 may play a role in manipulating non-cancerous surrounding cells and that measurement of ITGA3 and ITGB1 in urine exosomes has the potential to identify patients with metastatic PCa in a non-invasive manner.

Prevalence of Birt–Hogg–Dubé syndrome in patients with apparently primary spontaneous pneumothorax

Pneumothorax is classified “spontaneous pneumothorax” if there is no external force causing it and is classified as “primary spontaneous pneumothorax” (PSP) if there is no underlying lung disease. According to the guidelines of the British Thoracic Society (BTS), “no underlying lung disease” is based on history, physical examination and chest radiography [1]. Birt–Hogg–Dubé syndrome is probably the cause of pneumothorax in 5–10% of primary spontaneous pneumothorax patients http://ow.ly/FiIGS

Value of an Immediate Intravesical Instillation of Mitomycin C in Patients with Non–muscle-invasive Bladder Cancer: A Prospective Multicentre Randomised Study in 2243 patients

BACKGROUND The efficacy of an immediate single chemotherapy instillation after transurethral resection of a bladder tumour (TURBT) in patients with non-muscle-invasive bladder cancer (NMIBC) remains a topic of debate. Evidence is even more scarce when an immediate instillation is followed by adjuvant instillations. OBJECTIVE To compare the effect of a mitomycin C (MMC) instillation within 24h to an instillation 2 wk after TURBT in patients with NMIBC with or without adjuvant instillations. DESIGN, SETTING, AND PARTICIPANTS Between 1998 and 2003, 2844 NMIBC patients were randomised for immediate versus delayed MMC instillation after TURBT. Patients were categorised in low-risk (LOR), intermediate-risk (IMR), and high-risk (HIR) groups. Total numbers of instillations in these groups were 1, 9, and 15, respectively. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Primary end point was 3-yr recurrence risk for the IMR and HIR groups and 5-yr risk for the LOR group. Secondary outcomes were time to recurrence and incidence of adverse events. Analyses were performed with the log-rank test, Cox-regression, and χ2 test in SPSS. RESULTS AND LIMITATIONS A total of 2243 patients were eligible on an intention-to-treat basis. Recurrence risks were 43% and 46% in the LOR group (5-yr follow-up, p=0.11), 20% and 32% in the IMR group (3-yr follow-up, p=0.037), and 28% and 35% in the HIR group (3-yr follow-up, p=0.007), for an immediate and a delayed instillation, respectively. For all patients, the recurrence risk was 27% (95% confidence interval [CI], 24-30) in the immediate and 36% (95% CI, 33-39) in the delayed instillation group (p<0.001) with a 27% reduction in relative recurrence risk (hazard ratio: 0.73, 95% CI, 0.63-0.85, p<0.001). The incidence of adverse events did not differ significantly between treatment groups (immediate instillation 25%, delayed instillation 22%, p=0.08). The risk groups in our study differ slightly from the current guidelines, which is a limitation of our study. CONCLUSIONS An immediate, single instillation after TURBT reduces the recurrence risk in NMIBC patients, independent of the number of adjuvant installations. PATIENT SUMMARY A single instillation of chemotherapy after the resection of non-muscle-invasive bladder cancer reduces the recurrence risk, even if patients are treated with an adjuvant schedule of instillations.

A de novo FLCN mutation in a patient with spontaneous pneumothorax and renal cancer; a clinical and molecular evaluation

Birt–Hogg–Dubé syndrome (BHD) is an autosomal dominant condition due to germline FLCN (folliculin) mutations, characterized by skin fibrofolliculomas, lung cysts, pneumothorax and renal cancer. We identified a de novoFLCN mutation, c.499C>T (p.Gln167X), in a patient who presented with spontaneous pneumothorax. Subsequently, typical skin features and asymptomatic renal cancer were diagnosed. Probably, de novo FLCN mutations are rare. However, they may be under-diagnosed if BHD is not considered in sporadic patients who present with one or more of the syndromic features. Genetic and immunohistochemical analysis of the renal tumour indicated features compatible with a tumour suppressor role of FLCN. The finding that mutant FLCN was expressed in the tumour might indicate residual functionality of mutant FLCN, a notion which will be explored in future studies.

Survival after prostate brachytherapy in patients aged 60 years and younger

Study Type – Aetiology (prospective cohort)

Spontaneous pneumothorax as indicator for Birt-Hogg-Dubé syndrome in paediatric patients

BackgroundBirt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominantly inherited disorder caused by germline mutations in the folliculin (FLCN) gene. Clinical manifestations of BHD include skin fibrofolliculomas, renal cell cancer, lung cysts and (recurrent) spontaneous pneumothorax (SP). All clinical manifestations usually present in adults > 20 years of age.Case presentationsTwo non-related patients with (recurrent) pneumothorax starting at age 14 accompanied by multiple basal lung cysts on thoracic CT underwent FLCN germline mutation analysis. A pathogenic FLCN mutation was found in both patients confirming suspected BHD. The family history was negative for spontaneous pneumothorax in both families.ConclusionAlthough childhood occurrence of SP in BHD is rare, these two cases illustrate that BHD should be considered as cause of SP in children.

Protein Complexes in Urine Interfere with Extracellular Vesicle Biomarker Studies

Urine exosomes (extracellular vesicles; EVs) contain (micro)RNA (miRNA) and protein biomarkers that are useful for the non-invasive diagnosis of various urological diseases. However, the urinary Tamm-Horsfall protein (THP) complex, which forms at reduced temperatures, may affect EV isolation and may also lead to contamination by other molecules including microRNAs (miRNAs). Therefore, we compared the levels of three miRNAs within the purified EV fraction and THP- protein-network. Urine was collected from healthy donors and EVs were isolated by ultracentrifugation (UC), two commercial kits or sepharose size-exclusion chromatography (SEC). SEC enables the separation of EVs from protein-complexes in urine. After UC, the isolation of EV-miRNA was compared with two commercial kits. The EV isolation efficiency was evaluated by measuring the EV protein markers, Alix and TSG101, CD63 by Western blotting, or miR-375, miR-204 and miR-21 by RT-qPCR. By using commercial kits, EV isolation resulted in either low yields or dissimilar miRNA levels. Via SEC, the EVs were separated from the protein-complex fraction. Importantly, a different ratio was observed between the three miRNAs in the protein fraction compared to the EV fraction. Thus, protein-complexes within urine may influence EV-biomarker studies. Therefore, the characterization of the isolated EV fraction is important to obtain reproducible results.

Risk of disease flare with LHRH agonist therapy in men with prostate cancer: Myth or fact?

OBJECTIVES The traditional assumption of a linear relationship between serum testosterone and prostate cancer growth has been seriously challenged, as overwhelming evidence contradicts its basic principles. Luteinizing hormone-releasing hormone (LHRH) agonists are known to cause a peak in serum testosterone level in the initial weeks of treatment, and prevention of the clinical sequelae of testosterone flare by concomitant use of antiandrogens is recommended. Along the present biological concept that there appears to be a limit to the ability of androgens to stimulate prostate cancer growth, termed the saturation model, the use of antiandrogens to prevent this disease flare is questioned. The purpose of this review is to gain historical and modern evidence to provide an objective and up-to-date basis for clinical decision making. METHODS AND MATERIALS We performed a comprehensive research of the electronic databases PubMed and Embase until April 1, 2014. Studies with the subject of disease flare in men with prostate cancer on LHRH agonist therapy were included, as were studies that assessed the efficacy of antiandrogens to prevent this flare. Case reports were included as well. RESULTS Overall, 25 studies considering disease flare were included: 9 randomized clinical trials with an LHRH agonist and an LHRH agonist/antiandrogen arm, 14 observational studies evaluating LHRH agonists only, and 2 case reports. The incidence of disease flare was reported between 0% and 83% owing to a wide set of clinical, biochemical, and radiological factors evaluated. In some of the randomized clinical trials, a statistically significant reduction of the incidence of disease flare by concomitant use of antiandrogens was reported. Most of these historical studies report on subjective worsening of disease symptoms as outcome measure. More objective outcome measures such as the prostate-specific antigen level did not seem to increase to higher than the baseline values. CONCLUSIONS At present, there is a lack of compelling data showing definite disease progression during the short period of testosterone flare after initiation of LHRH agonist therapy. Based on the saturation model, presence of disease flare and the need to prevent this flare by concomitant use of antiandrogens might well be a misconception.

First-line non-cytotoxic therapy in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: a systematic review of 10 randomised clinical trials

The aim of this study is to systematically evaluate all available treatment options in chemotherapy‐naive patients with metastatic castration‐resistant prostate cancer (mCRPC). We systematically searched PubMed, EMBASE, and the Cochrane libraries up to 1 March 2016 for peer‐reviewed publications on randomised clinical trials (RCTs). RCTs were included if progression‐free survival (PFS), overall survival (OS), quality of life (QoL), or adverse events (AEs) were quantitatively evaluated. We assessed the risk of bias with the Cochrane Collaborations tool and graded the evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Groups approach. We included 25 articles, reporting on 10 unique RCTs describing seven different comparisons. In one RCT, a prolonged OS and PFS (high quality) were found with abiraterone and prednisone compared to placebo plus prednisone. In one RCT, a prolonged OS and PFS (high quality) were found with enzalutamide compared to placebo. In two RCTs, a prolonged OS (high and moderate quality) was found with 223radium compared to placebo, but its effect on PFS is unknown. In three RCTs, a prolonged OS (moderate quality) was found with sipuleucel‐T compared to placebo, but no prolonged PFS (low quality). In one RCT a prolonged PFS (high quality) was found with orteronel compared to placebo, but no prolonged OS (moderate quality). In one RCT, a prolonged OS (moderate quality) was found with bicalutamide compared to placebo, but its effect on PFS is unknown. In one RCT, a prolonged PFS (high quality) was found with enzalutamide compared to bicalutamide, but its effect on OS is unknown. The best evidence was found for abiraterone and enzalutamide for effective prolongation of OS and PFS to treat chemotherapy‐naive patients with mCRPC. However, taking both QoL and AEs into consideration, other treatment modalities could be considered for individual patients.

Relationship Between Body Mass Index and Serum Testosterone Concentration in Patients Receiving Luteinizing Hormone-releasing Hormone Agonist Therapy for Prostate Cancer

OBJECTIVE To evaluate the relationship between the body mass index (BMI) and serum testosterone concentrations in men receiving luteinizing hormone-releasing hormone (LHRH) agonist therapy for prostate cancer. MATERIALS AND METHODS A total of 66 white men were included in the present study. All subjects had received LHRH agonist therapy for ≥ 3 months. The BMI was calculated, and the subjects were classified as normal weight (i.e. BMI <25 kg/m(2)), overweight (BMI 25-30 kg/m(2)), or obese (BMI >30 kg/m(2)). The serum testosterone concentration was determined using the highly sensitive isotope dilution-liquid chromatography-tandem mass spectrometry technique. The sex hormone-binding globulin level was determined using an immunometric assay, and the free serum testosterone concentration was calculated. RESULTS The median serum testosterone concentration of the patients with a BMI <25 kg/m(2) was 5.5 ng/dL. The patients with a BMI of 25-30 kg/m(2) had a median serum testosterone concentration of 3.8 ng/dL. Those patients with a BMI >30 kg/m(2) had a median concentration of 5.7 ng/dL. No significant difference in the serum testosterone concentrations among the 3 groups was found. The sex hormone-binding globulin levels declined with an increasing BMI. The concentration of free testosterone was significantly greater in the obese men. CONCLUSION Using an ultrasensitive technique of serum testosterone measurement, the present data have shown that no difference exists in the serum testosterone concentration in the castrate range among normal weight, overweight, and obese patients receiving LHRH agonist therapy for prostate cancer. From our findings and current knowledge, more stringent follow-up or changes in dosage or dosage intervals of LHRH agonist therapy in those with a greater or high BMI is not warranted.