Distinct Infiltration of T Cell Populations in Bladder Cancer Molecular Subtypes.

Bladder cancer is a heterogenous disease, and molecular subtyping is a promising method to capture this variability. Currently, the immune compartment in relation to subtypes is poorly characterized. Here, we analyzed the immune compartment in bladder tumors and normal bladder urothelium with a focus on T cell subpopulations using flow cytometry and RNA sequencing. The results were investigated in relation to tumor invasiveness (NMIBC/MIBC) and molecular subtypes according to the Lund Taxonomy system. Whereas the NMIBC/MIBC differed in the overall immune infiltration only, the molecular subtypes differed both in terms of immune infiltration and immune compartment compositions. The Basal/Squamous (Ba/Sq) and genomically unstable (GU) tumors displayed increased immune infiltration compared to urothelial-like (Uro) tumors. Additionally, the GU tumors had a higher proportion of regulatory T cells within the immune compartment compared to Uro tumors. Furthermore, sequencing showed higher levels of exhaustion in CD8+ T cells from GU tumors compared to both Uro tumors and the control. Although no such difference was detected at the transcriptomic level in Uro tumors compared to the controls, CD8+ T cells in Uro tumors showed higher expression of several exhaustion markers at the protein level. Taken together, our findings indicate that depending on the molecular subtype, different immunotherapeutic interventions might be warranted.

Urodrill - a novel MRI-guided endoscopic biopsy technique to sample and molecularly classify muscle-invasive bladder cancer without fractionating the specimen during transurethral resection.

The current diagnostic pathway for patients with muscle-invasive bladder cancer (MIBC), which involves with computed tomography urography, cystoscopy, and transurethral resection of the bladder (TURB) to histologically confirm MIBC, delays definitive treatment. The Vesical Imaging-Reporting and Data System (VI-RADS) has been suggested for MIBC identification using magnetic resonance imaging (MRI), but a recent randomized trial reported misclassification in one-third of patients. We investigated a new endoscopic biopsy device (Urodrill) for histological confirmation of MIBC and assessment of molecular subtype by gene expression in patients with VI-RADS 4 and 5 lesions on MRI. In ten patients, Urodrill biopsies were guided by MR images to the muscle-invasive portion of the tumor via a flexible cystoscope under general anesthesia. During the same session, conventional TURB was subsequently performed. A Urodrill sample was successfully obtained in nine of ten patients. MIBC was verified in six of nine patients, and seven of nine samples contained detrusor muscle. In seven of eight patients for whom a Urodrill biopsy sample was subjected to RNA sequencing, single-sample molecular classification according to the Lund taxonomy was feasible. No complications related to the biopsy device occurred. A randomized trial comparing this new diagnostic pathway for patients with VI-RADS 4 and 5 lesions and the current standard (TURB) is warranted. Patient summary: We report on a novel biopsy device for patients with muscle-invasive bladder cancer that facilitates histology analysis and molecular characterization of tumor samples.

Reducing recurrence in non-muscle-invasive bladder cancer by systematically implementing guideline-based recommendations: effect of a prospective intervention in primary bladder cancer patients.

Objective: In non-muscle-invasive bladder cancer (NMIBC), local recurrence after transurethral resection of the bladder (TURB) is common. Outcomes vary between urological centres, partly due to the sub-optimal surgical technique and insufficient application of measures recommended in the guidelines. This study evaluated early recurrence rates after primary TURB for NMIBC before and after introducing a standardized treatment protocol. Methods: Medical records of all patients undergoing primary TURB for NMIBC in 2010 at Skåne University Hospital, Malmö, Sweden, were reviewed. A new treatment protocol for NMIBC was defined and introduced in 2013, and results documented during the first year thereafter were compared with those recorded in 2010 prior to the intervention. The primary endpoint was early recurrence at first control cystoscopy. Comparisons were made by Chi-square analysis and Fisher's exact test. Recurrence-free survival (RFS) in the two cohorts was also investigated. Results: TURB was performed on 116 and 159 patients before and after the intervention, respectively. The early recurrence rate decreased from 22% to 9.6% (p = 0.005) at the first control cystoscopy after treatment. Residual/Recurrent tumour at the first control cystoscopy after the primary TURB (i.e. at second-look resection or first control cystoscopy) decreased from 31% to 20% (p = 0.038). The proportion of specimens containing muscle in T1 tumours increased from 55% to 94% (p < 0.001). RFS was improved in the intervention group (HR = 0.65, CI = 0.43-1.0; p = 0.05). Conclusions: Introduction of a standardized protocol and reducing the number of surgeons for primary treatment of NMIBC decreased the early recurrence rate from 22% to 9.6% and lowered the recurrence incidence by 35%.