Abstract
Upper tract urothelial cancer (UTUC) are rare subsets of urothelial cancer, which typically present with more aggressive course. Molecular markers stratifying urothelial tumors as luminal subtype and non-luminal subtype tumors have been proposed to select patients who may have greater or lesser benefit from neoadjuvant systemic therapy in bladder cancer, though not yet evaluated in UTUC. Here, a single-institution study retrospectively obtained clinical and genomic information in patients with UTUC and evaluated four patient tumors using the Decipher Bladder(®) assay and Foundation Medicine(®) test. All four patients had non-luminal molecular subtype including basal (N = 4) and mixed basal/claudin-low (N = 2) subtypes. The best clinical response achieved was stable disease in a patient who had basal/claudin-low subtype with residual ypT3 after neoadjuvant chemotherapy. For the remaining three patients, all were treated with platinum-based chemotherapy for eventual metastatic disease but all three showed progressive disease with limited overall survival, highlighting their aggressive course. The non-luminal subtype and lack of FGFR alteration may partly explain the poor overall outcomes while the real-world benefit of next generation sequencing for clinical use in UTUC patients require further clarification in a larger cohort study.