Upper urinary tract urothelial carcinoma (UTUC) patients have poor outcomes and a high risk of future urothelial carcinoma of the bladder (UCB) after radical surgery. Currently, diagnostic tools that predict the risk of a UCB recurrence are lacking and more effective therapies are needed to improve survival.
Using two retrospective cohorts of in total 201 UTUC + 53 UCB recurrences (discovery set) and a prospective cohort of 150 UTUC samples (validation set) together with so far 11 UCB recurrences we aim to determine whether:
1) UTUC and UCB recurrences are clonally related, enabling surveillance by molecular urine diagnostics
2) UTUC is characterized by molecular alterations that lead to high tumor mutational burden (TMB), offering a target for immunotherapy
Next generation sequencing of 571 genes, microsatellite instability analysis, and immunohistochemistry are being used to assess TMB, mismatch repair deficiency, immune infiltration and protein-based subtypes.
This project will provide novel insights on the clonality of UTUC and paired UCB. Preliminary data analysis shows a clonal origin in the vast majority of the UTUC and paired UCB. This can be applied to replace cystoscopies by the development of patient-friendly molecular urine assays for surveillance of the bladder after surgery. Moreover, it enables the identification of new actionable genomic alterations of UTUC that serve as targets for therapy, such as precision-guided immunotherapy in UTUC patients with high TMB or FGFR-targeted therapy in UTUC patients with FGFR alterations, leading to durable responses and improved outcome.