Upregulation of shelterin and CST genes and longer telomeres are associated with unfavorable prognostic characteristics in prostate cancer.

INTRODUCTION: Search for new clinical biomarkers targets in prostate cancer (PC) is urgent. Telomeres might be one of these targets. Telomeres are the extremities of linear chromosomes, essential for genome stability and control of cell divisions. Telomere homeostasis relies on the proper functioning of shelterin and CST complexes. Telomeric dysfunction and abnormal expression of its components are reported in most cancers and are associated with PC. Despite this, there are only a few studies about the expression of the main telomere complexes and their relationship with PC progression. We aimed to evaluate the role of shelterin (POT1, TRF2, TPP1, TIN2, and RAP1) and CST (CTC1, STN1, and TEN1) genes and telomere length in the progression of PC. METHODS: We evaluated genetic alterations of shelterin and CST by bioinformatics in samples of localized (n = 499) and metastatic castration-resistant PC (n = 444). We also analyzed the expression of the genes using TCGA (localized PC n = 497 and control n = 152) and experimental approaches, with surgical specimens (localized PC n = 81 and BPH n = 10) and metastatic cell lines (LNCaP, DU145, PC3 and PNT2 as control) by real-time PCR. Real-time PCR also determined the telomere length in the same experimental samples. All acquired data were associated with clinical parameters. RESULTS: Genetic alterations are uncommon in PC, but POT1, TIN2, and TEN1 showed significantly more amplifications in the metastatic cancer. Except for CTC1 and TEN1, which are differentially expressed in localized PC samples, we did not detect an expression pattern relative to control and cell lines. Nevertheless, except for TEN1, the upregulation of all genes is associated with a worse prognosis in localized PC. We also found that increased telomere length is associated with disease aggressiveness in localized PC. CONCLUSION: The upregulation of shelterin and CST genes creates an environment that favors telomere elongation, giving selective advantages for localized PC cells to progress to more aggressive stages of the disease.

The landscape of biomedical research funding in Brazil: a current overview.

OBJECTIVE: The objective of this narrative review is to discuss the current state of research funding in Brazil. MATERIALS AND METHODS: This study is based on the most recent edition of the course Funding for Research and Innovation in the University of Sao Paulo School of Medicine which was a three-day course with 12 hours of instruction. The course brought together leading experts in the field to comprehensively discuss the current state of research funding in Brazil. Each speaker provided a presentation on a specific topic related to research funding. After the workshop, speakers assembled relevant topics in this manuscript. RESULTS: collaborative research is critical for securing research funding. It optimizes proposal competitiveness, amplifies societal impact, and manages risks effectively. As such, fostering and supporting these collaborations is paramount for both researchers and funding agencies. To maintain the highest integrity in research, investigators involved in these collaborations must disclose any relationships that could potentially influence the outcomes or interpretation of their projects. CONCLUSIONS: In Brazil, the mainstay of research funding stems from public entities, with agencies such as CNPq, CAPES, and state bodies like FAPESP, FAPERJ, FAPEMIG and others at the forefront. Concurrently, industry funding offers viable pathways, especially through industry-sponsored studies, investigator-led projects, and collaborative initiatives. The Brazilian funding landscape is further enriched by innovative platforms, including crowdfunding and the contributions of institutions like the Serrapilheira Institute. Internationally, esteemed organizations such as the National Institutes of Health (NIH) and the Bill & Melinda Gates Foundation stand out as potential funders.

Evaluation of AR, AR-V7, and p160 family as biomarkers for prostate cancer: insights into the clinical significance and disease progression.

PURPOSE: To assess the role of the p160 family, AR, and AR-V7 in different initial presentations of prostate cancer and their association with clinical endpoints related to tumor progression. METHODS: The study sample comprises 155 patients who underwent radical prostatectomy and 11 healthy peripheral zone biopsies as the control group. Gene expression was quantified by qPCR from the tissue specimens. The statistical analysis investigated correlations between gene expression levels, associations with disease presence, and clinicopathological features. Additionally, ROC curves were applied for distinct PCa presentations, and time-to-event analysis was used for clinical endpoints. RESULTS: The AR-V7 diagnostic performance for any PCa yielded an AUC of 0.77 (p < 0.05). For locally advanced PCa, the AR-V7 AUC was 0.65 (p < 0.05). Moreover, the metastasis group had a higher expression of SRC-1 than the non-metastatic group (p < 0.05), showing a shorter time to metastasis in the over-expressed group (p = 0.005). Patients with disease recurrence had super-expression of AR levels (p < 0.0005), with a shorter time-to-recurrence in the super-expression group (p < 0.0001). CONCLUSION: Upregulation of SRC-1 indicates a higher risk of progression to metastatic disease in a shorter period, which warrants further research to be applied as a clinical tool. Additionally, AR may be used as a predictor for PCa recurrence. Furthermore, AR-V7 may be helpful as a diagnostic tool for PCa and locally advanced cancer, comparable with other investigated tools.

The Effect of Gene Editing by CRISPR-Cas9 of miR-21 and the Indirect Target MMP9 in Metastatic Prostate Cancer.

Prostate cancer (PCa) has a high prevalence and represents an important health problem, with an increased risk of metastasis. With the advance of CRISPR-Cas9 genome editing, new possibilities have been created for investigating PCa. The technique is effective in knockout oncogenes, reducing tumor resistance. MMP9 and miR-21 target genes are associated with PCa progression; therefore, we evaluated the MMP-9 and miR-21 targets in PCa using the CRISPR-Cas9 system. Single guide RNAs (sgRNAs) of MMP9 and miR-21 sequences were inserted into a PX-330 plasmid, and transfected in DU145 and PC-3 PCa cell lines. MMP9 and RECK expression was assessed by qPCR, WB, and IF. The miR-21 targets, integrins, BAX and mTOR, were evaluated by qPCR. Flow cytometry was performed with Annexin5, 7-AAD and Ki67 markers. Invasion assays were performed with Matrigel. The miR-21 CRISPR-Cas9-edited cells upregulated RECK, MARCKS, BTG2, and PDCD4. CDH1, ITGB3 and ITGB1 were increased in MMP9 and miR-21 CRISPR-Cas9-edited cells. Increased BAX and decreased mTOR were observed in MMP9 and miR-21 CRISPR-Cas9-edited cells. Reduced cell proliferation, increased apoptosis and low invasion in MMP9 and miR-21 edited cells was observed, compared to Scramble. CRISPR-Cas9-edited cells of miR-21 and MMP9 attenuate cell proliferation, invasion and stimulate apoptosis, impeding PCa evolution.

Intratumoral Restoration of miR-137 Plus Cholesterol Favors Homeostasis of the miR-137/Coactivator p160/AR Axis and Negatively Modulates Tumor Progression in Advanced Prostate Cancer.

MicroRNAs (miRNAs) have gained a prominent role as biomarkers in prostate cancer (PCa). Our study aimed to evaluate the potential suppressive effect of miR-137 in a model of advanced PCa with and without diet-induced hypercholesterolemia. In vitro, PC-3 cells were treated with 50 pmol of mimic miR-137 for 24 h, and gene and protein expression levels of SRC-1, SRC-2, SRC-3, and AR were evaluated by qPCR and immunofluorescence. We also assessed migration rate, invasion, colony-forming ability, and flow cytometry assays (apoptosis and cell cycle) after 24 h of miRNA treatment. For in vivo experiments, 16 male NOD/SCID mice were used to evaluate the effect of restoring miR-137 expression together with cholesterol. The animals were fed a standard (SD) or hypercholesterolemic (HCOL) diet for 21 days. After this, we xenografted PC-3 LUC-MC6 cells into their subcutaneous tissue. Tumor volume and bioluminescence intensity were measured weekly. After the tumors reached 50 mm3, we started intratumor treatments with a miR-137 mimic, at a dose of 6 µg weekly for four weeks. Ultimately, the animals were killed, and the xenografts were resected and analyzed for gene and protein expression. The animals' serum was collected to evaluate the lipid profile. The in vitro results showed that miR-137 could inhibit the transcription and translation of the p160 family, SRC-1, SRC-2, and SRC-3, and indirectly reduce the expression of AR. After these analyses, it was determined that increased miR-137 inhibits cell migration and invasion and impacts reduced proliferation and increased apoptosis rates. The in vivo results demonstrated that tumor growth was arrested after the intratumoral restoration of miR-137, and proliferation levels were reduced in the SD and HCOL groups. Interestingly, the tumor growth retention response was more significant in the HCOL group. We conclude that miR-137 is a potential therapeutic miRNA that, in association with androgen precursors, can restore and reinstate the AR-mediated axis of transcription and transactivation of androgenic pathway homeostasis. Further studies involving the miR-137/coregulator/AR/cholesterol axis should be conducted to evaluate this miR in a clinical context.

The influence of interstitial cells of Cajal density in the outcomes of pyeloplasty in adults: A prospective analysis.

PURPOSE: To evaluate if the density of interstitial cells of Cajal (ICC) in the ureteropelvic junction (UPJ) influences the outcomes of pyeloplasty in adults. METHODS: Twenty-three patients with the diagnosis of ureteropelvic junction obstruction (UPJO) that underwent laparoscopic dismembered pyeloplasty were included. ICC density was measured using immunohistochemistry reaction for c-KIT expression in the resected UPJ segment. Pyeloplasty outcome was evaluated by patient self-report pain, urinary outflow using DTPA renogram and hydronephrosis assessment using ultrasound (US) at 12 months of follow-up. A logistic regression analysis was performed to assess the association of pyeloplasty outcomes and ICC density. RESULTS: Low, moderate, and high ICC density were present in 17.4%, 30.4%, and 52.2% of the patients, respectively. Complete pain resolution was observed in 100%, 85.7%, and 75% of patients with low, moderate and high ICC density, respectively (p = 0.791). DTPA renogram improved in 75%, 85.7%, and 91.7% of patients with low, moderate and high ICC density, respectively (p = 0.739). Hydronephrosis improved in 25%, 85.7%, and 91.7% of patients with low, moderate and high ICC density, respectively (p = 0.032). CONCLUSIONS: Patients with high ICC density have a significant amelioration of hydronephrosis after pyeloplasty. However, ICC density is not associated with functional outcomes.

Cholesterol Triggers Nuclear Co-Association of Androgen Receptor, p160 Steroid Coactivators, and p300/CBP-Associated Factor Leading to Androgenic Axis Transactivation in Castration-Resistant Prostate Cancer.

BACKGROUND/AIMS: Cholesterol modulates intratumoral androgenic signaling in prostate cancer; however, the molecular mechanisms underlying these changes in castration-resistant prostate cancer (CRPC) are not fully elucidated. Herein, we investigated the effect of cholesterol on androgen receptor (AR) coactivators expression and tumorigenesis in vitro and in vivo. METHODS: Herein, we monitored the expression of AR coactivators (SRC-1, 2, 3 and PCAF) genes in PC-3 cells exposed to 2µg/mL of cholesterol for 8 hours by qPCR. We also performed cell migration at 0, 8, 24, 48 and 72h and flow cytometry assays (viability, apoptosis, and cell cycle) after a 24h exposure. Immunofluorescence assay was performed to evaluate the protein expression of the AR coactivators. Additionally, in vivo experiments were conducted using 22 male NOD/SCID mice. Mice were fed a standard (Control) or hypercholesterolemic (HCOL) diet for 21 days and then subcutaneously implanted with PC-3 cells. The tumor volume was calculated every two days, and after four weeks, the tumors were resected, weighed, and the serum lipid profile was measured. We also measured the intratumoral lipid profile and AR coactivators gene and protein expression by qPCR and Western Blot, respectively. Intratumor testosterone and dihydrotestosterone (DHT) concentrations were determined using ELISA. RESULTS: Cholesterol up-regulated the gene expression of coactivators SRC-1, SRC-2, SRC-3and PCAF, increasing AR expression in PC-3 cells. Next, cholesterol-supplemented PC-3 cells exhibited increased cell migration and altered cell cycle phases, leading to changes in proliferation and reduced apoptosis. We found that SRC-1, SRC-2, SRC-3 and PCAF proteins co-localized in the nucleus of cholesterol-supplemented cells and co-associate with AR. In the in vivo model, the hypercholesterolemic (HCOL) group displayed higher serum total and intratumoral cholesterol levels, increased testosterone and dihydrotestosterone concentrations, and up-regulated AR coactivator expression. The tumor volume of the HCOL group was significantly higher than the control group. CONCLUSION: Our findings revealed that increased nuclear translocation of the coactivators leads to up-regulated AR gene and protein expression, potentially influencing tumor progression. Studies targeting cholesterol-modulated changes in AR coactivator expression may provide insights into the molecular mechanisms associated with the CRPC phenotype.

Can we use Ki67 expression to predict prostate cancer aggressiveness?

INTRODUCTION: specialists have an urge for biomarkers that can discriminate indolent prostate cancer from aggressive tumors. Ki67 is a proliferation marker, and its expression is associated with the aggressiveness of several cancers. OBJECTIVE: analyze the expression of Ki67 in prostate cancer samples correlating with the aggressiveness of the disease. METHODS: Ki67 mRNA levels were determined utilizing data from a TCGA cohort (Tumor(n)=492 and control(n)=52). The protein expression was determined on 94 biopsies from patients by immunohistochemical assay. RESULTS: in mRNA, the Ki67 upregulation is associated with cancer tissue (p<0.0001) and worst disease-free survival (p=0.035). The protein upregulation is associated with increase of the ISUP score (p<0.0001), cancer stage (p=0.05), biochemical recurrence (p=0.0006) and metastasis (p<0.0001). We also show a positive correlation between Ki67 expression and ISUP score (r=0.5112, p<0.0001) and disease risk stratification (r=0.3388, p=0.0009). Ki67 expression is a factor independently associated with biochemical recurrence (p=0.002) and metastasis (p<0.0001). Finally, the patients with high Ki67expression shows better survival regarding biochemical recurrence (p=0.008) and metastasis (p=0.056). Patients with high Ki67 expression are 2.62 times more likely to develop biochemical recurrence (p=0.036). CONCLUSION: Ki67 upregulation is associated with prostate cancer aggressiveness.

Single-use flexible ureteroscopes: update and perspective in developing countries. A narrative review

ABSTRACT Flexible ureteroscopy is a well-established method for treatment of urinary stones but flexible ureteroscopes are expensive and fragile devices with a very limited lifetime. Since 2006 with the advent of digital flexible ureteroscopes a great evolution has occurred. The first single-use flexible ureteroscope was launched in 2011 and new models are coming to the market. The aim of this article is to review the characteristics of these devices, compare their results with the reusable devices and evaluate the cost-benefits of adopting single-use flexible ureteroscopes in developing countries. Materials and Methods: an extensive review of articles listed at PubMed and published between 2000 and 2021 was performed. Results: Single-use flexible ureteroscopes have a shaft with 65 to 68cm length and weight between 119 and 277g. Their deflection goes up to 300 degrees. Their stone-free rates vary between 60 and 95% which is comparable to reusable scopes and operative times ranges from 54 to 86 minutes which are lower when compared to reusable flexible scopes. Their costs vary between 800 and 3180 US dollars. Conclusion: single-use flexible ureteroscopes are lighter and have superior quality of image when compared to fiberoptic ones. There are no definite data showing a higher stone-free rate or less complications with the use of single-use flexible ureteroscopes. Each institution must perform a cost-benefit analysis before making the decision of adopting or not such devices depending on the local circumstances.

Holmium Laser Resection of Large Bladder Tumors: Technique Description, Feasibility, and Histopathological Quality Analysis.

BACKGROUND: The HoLERBT (Holmium Laser En-bloc Resection of Bladder Tumors) has emerged as an alternative to classical TURBT (Transurethral Resection of Bladder Tumor). Recent randomized trial and meta-analysis corroborate with the benefits in pathological analysis, perioperative and long-term oncological outcomes.1-3 However, the treatment of large tumors and the technique of extraction from the bladder is a problem to be overcome.1,4 OBJECTIVE: To describe the laser resection of bladder tumors and demonstrate the feasibility of this procedure even for large tumors throughout a series of cases. It is also discussed the quality of the histopathological analysis. METHODS: A series of 8 cases randomized selected to be the pilot for a trial comparing TURBT and HoLERBT in large tumors (>3 cm) in progress was analyzed (Brazilian Registry of Clinical Trials number RBR-67npwrk). The perioperative data and 1-year outcomes were assessed and the quality of histopathological analysis after morcellation was evaluated in terms of histopathology, grade, and stage. The entire procedure of one case is shown in a step-by-step video. RESULTS: The mean follow-up was 12.6 months. The mean age was 59.6 (42-85) years, and the mean tumor size was 4.7 (4-8) cm. All the resections were En-bloc. There were 2 cases of NMIBC, 4 cases of MIBC, 1 paraganglioma, and 1 adenocarcinoma. The histopathological analysis confirmed the presence of detrusor muscle layer and accurate diagnosis and staging in all cases (100%). There were no perioperative Clavien-Dindo > 1 complications, no blood transfusion, and no bladder perforations. The histopathology analysis reveals excellent quality without artifacts of fulguration. CONCLUSION: The holmium laser resection followed by morcellation of large bladder tumors is a feasible procedure. No complications occurred in our series of cases and all cases provided excellent material for histopathological analysis.

A Prospective, Randomized Trial Comparing the Outcomes of Open vs Laparoscopic Partial Nephrectomy.

PURPOSE: Partial nephrectomy is the standard treatment for renal tumors <7 cm, and the trend toward minimally invasive surgery has increased. However, data that could support its use and benefits are still lacking. MATERIALS AND METHODS: We conducted a prospective, randomized controlled trial comparing surgical, functional and oncologic outcomes in patients undergoing open partial nephrectomy (OPN) or laparoscopic partial nephrectomy (LPN). Randomization was 1:1 to OPN or LPN for the treatment of renal tumors <7 cm. The primary endpoint was surgical complications up to 90 days after surgery. Secondary outcomes were comparison of surgical, oncologic and functional results. RESULTS: We randomized 208 patients between 2012 and 2020 (110 with OPN vs 98 with LPN). Operative data showed no differences in operative time, warm ischemia time, estimated blood loss, transfusions or length of hospital stay. Zero ischemia was more frequent in the OPN (35.4% vs 15.5%, p=0.02). OPN was associated with more abdominal wall complications (31.2% vs 13.1%, p=0.004). Regarding oncologic outcomes, no differences were noted. The LPN group had less kidney function reduction at 3 (-5.2% vs -10%, p=0.04; CI 0.09 to 9.46) and 12 months after surgery (-0.8% vs -6.3%, p=0.02; CI 1.18 to 12.95), and a lower rate of downstaging on the chronic kidney disease classification at 12 months (14.1% vs 32.6%, p=0.006). CONCLUSIONS: Surgical and oncologic outcomes of LPN were similar to OPN. Minimally invasive surgery may provide better preservation of kidney function. More studies, especially those involving robotic surgery, are necessary to confirm our findings.

Combined spinal and general anesthesia attenuate tumor promoting effects of surgery. An experimental animal study.

Background: Radical prostatectomy, a standard management approach for localized Prostate Cancer (PC), may cause a stress response associated with immune modulating effects. Regional anesthesia was hypothesized to reduce the immune effects of surgery by minimizing the neuroendocrine surgical stress response, thus mitigating tumor cells dissemination. Our primary objective was to investigate whether the use of spinal blocks attenuates PC tumor cells dissemination on an animal model. We also assessed the number of circulating NK cells and the amount of inflammatory and anti-inflammatory cytokines. Materials and methods: A subcutaneous tumor model, with PC-3M cell line transfected with a luciferase-producing gene (PC-3M-luc-C6) was used. After proper tumor establishment and before tumors became metastatic, animals were submitted to tumor excision surgeries under general or combined (general and spinal) anesthesia. A control group was only anesthetized with general anesthesia. Results: The subcutaneous tumor model with PC-3M-luc-C6 cells was effective in causing distant metastasis after 35 days. The number of circulating tumor cells increased in animals that underwent surgery under general anesthesia alone compared to the group submitted to combined anesthesia. Interleukin 6 levels were different in all groups, with increase in the general anesthesia group. Conclusion: Our results suggest that combination of spinal and general anesthesia may attenuate the suppression of innate tumor immunity and it might be related to a reduction in the neuroendocrine response to surgery. Institutional protocol number: Animal Ethics Committee 1332/2019.

Pan-cancer analysis reveals that CTC1-STN1-TEN1 (CST) complex may have a key position in oncology.

Telomere dysfunction is one of the hallmarks of cancer, which puts telomere-associated genes in a prominent position in oncology. The CTC1-STN1-TEN1 (CST) complex is vital for telomere maintenance and participates in several steps of DNA metabolism, such as repair and replication, essential functions for malignant cells. Despite this, little is known about these genes in cancer biology. Here, using bioinformatics tools, we performed a study in 33 cancer types and over 10,000 TCGA samples analyzing the role of the CST complex in cancer. We obtained the somatic landscape and gene expression patterns of each of the subunits of the complex studied. Furthermore, we show that CST is important for genetic stability and nucleic acid metabolism in cancer. We identify possible interactors, transcription factors, and microRNAs associated with CST and two drugs that may disrupt their pathways. In addition, we show that CST gene expression is associated with cancer survival and recurrence in several tumor types. Finally, we show negative and positive correlations between immune checkpoint genes and CST in different types of cancer. With this work, we corroborate the importance of these genes in cancer biology and open perspectives for their use in other works in the field.

Grafting Area Reduction in Peyronie's Disease Surgery: Comparative Assessment Between Double Y Vs iGrafter APP Using 3D-Printed Penile Models.

BACKGROUND: The use of plaque incision and graft techniques (PIG) for the treatment of severe Peyronie's disease (PD), may lead to erectile dysfunction (ED); graft size is 1 of the contributing factors for post-PIG ED. Recently the iGrafter software APP was introduced using a mathematical algorithm to distribute the incisions along the penile length resulting in a smaller grafting area. AIM: Compare 2 PIG techniques, the Double-Y(DY) and iGrafter, in 3 main aspects: (i) Total grafting area; (ii) The variation in calculating the grafting to be used; (iii) time to perform the PIG. METHODS: Six urologists with expertise in sexual medicine performed both techniques twice using four 3-D validated training models for PD with a standard 60° uniplanar dorsal curvature. OUTCOMES: The graft areas and operative partial and total time for each step of the operation were recorded for each procedure. Unpaired t-test and the coefficient of variation for graft area across surgeons was calculated comparing both techniques. RESULTS: For all surgeons, the use of iGrafter resulted in 2 grafts, for the DY technique in 1 graft. Overall, TT for the iGrafter was significantly longer than for DY technique (49.4 ± 11 vs 40.7 ± 5.7 minute; P = .02), The iGrafter grafting area was significantly smaller (11.6 ± 1.2 vs 23.3 ± 5.4 cm2; P: .01), representing a 50.2% area reduction when compared to the DY. The variation of graft area, using the iGrafter also yielded a more consistent graft across all surgeons (CV = 10.56% vs 23.28%). CLINICAL SIGNIFICANCE: The iGrafter, when compared to DY technique, reduced the graft area by 50%, which potentially means less erectile dysfunction. STRENGTHS AND LIMITATIONS: Our study eliminates anatomical variations found in a real clinical case making it possible to compare surgical techniques with the same penile anatomy. However, the 3D-printed model cannot replicate the living human tissue property preventing a simulation close to actual surgery. CONCLUSION: The use of the iGrafter software for PIG surgery has shown to be a promising technique for severe PD management resulting in smaller graft size (about 50% smaller when compared to the DY), although it might be more time-consuming. Tourchi A, Nascimento B, de Freita Miranda A, et al. Grafting Area Reduction in Peyronie's Disease Surgery: Comparative Assessment Between Double Y Vs iGrafter APP Using 3D-Printed Penile Models. J Sex Med 2022;19:669-675.

Single-use flexible ureteroscopes: update and perspective in developing countries. A narrative review.

Flexible ureteroscopy is a well-established method for treatment of urinary stones but flexible ureteroscopes are expensive and fragile devices with a very limited lifetime. Since 2006 with the advent of digital flexible ureteroscopes a great evolution has occurred. The first single-use flexible ureteroscope was launched in 2011 and new models are coming to the market. The aim of this article is to review the characteristics of these devices, compare their results with the reusable devices and evaluate the cost-benefits of adopting single-use flexible ureteroscopes in developing countries. MATERIALS AND METHODS: an extensive review of articles listed at PubMed and published between 2000 and 2021 was performed. RESULTS: Single-use flexible ureteroscopes have a shaft with 65 to 68cm length and weight between 119 and 277g. Their deflection goes up to 300 degrees. Their stone-free rates vary between 60 and 95% which is comparable to reusable scopes and operative times ranges from 54 to 86 minutes which are lower when compared to reusable flexible scopes. Their costs vary between 800 and 3180 US dollars. CONCLUSION: single-use flexible ureteroscopes are lighter and have superior quality of image when compared to fiberoptic ones. There are no definite data showing a higher stone-free rate or less complications with the use of single-use flexible ureteroscopes. Each institution must perform a cost-benefit analysis before making the decision of adopting or not such devices depending on the local circumstances.

Supine versus Prone Percutaneous Nephrolithotomy for Complex Stones: A Multicenter Randomized Controlled Trial.

PURPOSE: High-quality evidence comparing supine to prone percutaneous nephrolithotomy (PCNL) for the treatment of complex stones is lacking. This study aimed to compare the outcomes of supine position (SUP) and prone position (PRO) PCNL. MATERIALS AND METHODS: A noninferior randomized controlled trial was performed according to the CONSORT (Consolidated Standards for Reporting Trials) criteria. The inclusion criteria were patients over 18 years of age with complex stones. SUP was performed in the Barts flank-free modified position. Except for positioning, all the surgical parameters were identical. The primary outcome was the difference in the success rate on the first postoperative day (POD1) between groups. The secondary outcome was the difference in the stone-free rate (SFR) on the 90th postoperative day (final SFR). A noninferiority margin of 15% was used. Demographic, operative, and safety variables were compared between the groups. Statistical significance was set at p <0.05. RESULTS: Overall, 112 patients were randomized and their demographic characteristics were comparable. The success rates on POD1 were similar (SUP: 62.5% vs PRO: 57.1%, p=0.563). The difference observed (-5.4%) was lower than the predefined limit. The final SFRs were also similar (SUP: 55.4% vs PRO: 50.0%, p=0.571). SUP had a shorter operative time (mean±SD 117.9±39.1 minutes vs 147.6±38.8 minutes, p <0.001) and PRO had a higher rate of Clavien ≥3 complications (14.3% vs 3.6%, p=0.045). CONCLUSIONS: Positioning during PCNL for complex kidney stones did not impact the success rates; consequently, both positions may be suitable. However, SUP might be associated with a lower high-grade complication rate.