Tryptophan-kynurenine ratio as a biomarker of bladder cancer.

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.

Tip bendable suction ureteral access sheath versus traditional sheath in retrograde intrarenal stone surgery: an international multicentre, randomized, parallel group, superiority study.

Background: Retrograde intrarenal surgery (RIRS) is the main treatments for upper urinary tract stones. The Ureteral Access Sheath (UAS) serves as a supplementary tool, facilitating direct kidney access during RIRS. High quality of evidence comparing tip bendable suction ureteral access sheath (S-UAS) with traditional UAS in RIRS for the treatment of renal and ureteral stones is lacking. The purpose of the study is to compare the efficacy and safety of S-UAS with traditional UAS in RIRS for the treatment of renal or ureteral stones ≤30 mm. Methods: An international, multicenter, and superiority randomized controlled trial included 320 intention-to-treat patients across 8 medical centers in China, the Philippines, Malaysia and Turkey from August 2023 to February 2024. The inclusion criteria were patients ≥18 years old with renal or ureteral stones ≤30 mm. RIRS was performed using either S-UAS or traditional UAS. The primary outcome was the immediately stone-free rate (SFR). Secondary outcomes included SFR 3 months after operation, operating time, hospital stay, auxiliary procedures, complications (using the Clavien-Dindo grading system), and improvement in the Quality of Life (QoL) score. Differences between proportions [risk difference (RD)]/means [mean difference (MD)] and 95% confidence intervals (CI) were presented. This study is registered at ClinicalTrials.gov: NCT05952635. Findings: The S-UAS group demonstrated a significantly higher immediately SFR (81.3% versus 49.4%; RD 31.9%; 95% CI 22.5%-41.7%; p = 0.004) compared to the traditional UAS group, as determined by the one-side superiority test. Additionally, the S-UAS group exhibited a higher SFR at 3 months post-operation (87.5% versus 70.0%; RD 17.5%; 95% CI 8.7%-26.3%; p < 0.001), lower postoperative fever rate (RD -11.9%; 95% CI -18.7% to -4.9%; p < 0.001), reduced use of stone baskets (RD -70.6%; 95% CI -77.8% to -63.5%; p < 0.001), and better QoL improvement (MD 7.25; 95% CI 2.21-12.29; p = 0.005). No statistically significant differences were observed in operation time, hospital stay, or the need for second-stage RIRS. Interpretation: In RIRS for upper urinary tract stones ≤30 mm, S-UAS exhibited superior performance compared to traditional UAS, demonstrating higher SFR, reduced postoperative fever rate, and improved QoL outcomes. S-UAS emerges as a prudent and advantageous alternative to traditional UAS for RIRS. Funding: National Natural Science Foundation of China and Guangdong Province, and Zhejiang Medicine and Health Program.

Comparing outcomes of transperineal to transrectal prostate biopsies performed under local anaesthesia.

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.

Embryonal rhabdomyosarcoma of the adult urinary bladder: a rare case report of misclassification as inflammatory myofibroblastic tumor.

Embryonal rhabdomyosarcoma (ERMS) of the adult urinary bladder is a rare malignant tumour. Inflammatory myofibroblastic tumour (IMT) of the bladder is a benign genitourinary tumour that may appear variable histologically but usually lacks unequivocal malignant traits. Techniques like flow cytometry and immunohistochemistry may be used to differentiate these two tumours. Our patient, a 46-year-old male, had rapidly recurring lower urinary tract symptoms after two transurethral resections of the prostate. He subsequently underwent a transvesical prostatectomy which showed IMT on histology. However, his symptoms did not resolve and an open resection done at our institution revealed a 6 cm tumour arising from the right bladder neck. This time, histology was ERMS with diffuse anaplasia of the bladder. Rapid recurrence of urinary symptoms with prostate regrowth after surgery is unusual. Differential diagnoses of uncommon bladder malignancies should be considered if there is an inconsistent clinical course as treatment approaches are different.