Upper Urinary Tract Urothelial Carcinomas are rare, aggressive tumors, accounting for 5 to 10% of all urothelial tumors. These include tumors which develop in the renal cavities (renal pelvis, calices) and ureteral tumors. Nephro-ureterectomy is the standard treatment but 80% of patients will have a relapse within 2 years. Only one trial has (Birtle et al. 2020), has shown the interest of postoperative chemotherapy. Neoadjuvant systemic treatment seems particularly interesting for a population which is going to undergo a nephronic loss and therefore reduction in kidney function which is likely to make patients ineligible for cisplatin. In favor of additional immunotherapy, it has been described that upper excretory tract tumors have a high immunogenic potential with a high rate of microsatellite instability.

From surgical samples of patient tumors obtained after nephroureterectomy or biopsy material collected before treatment, we are going to generate patient-derived cell lines and xenograft models in the mouse. A recent publication has demonstrated the feasibility of this approach by specifying that the capture rate of tumor cells is 50% for patient-derived xenografts and 25% for patient-derived cells (Coleman et al. 2020). As tumors harvested from biopsies do not grow in patient-derived xenografts,we plan to graft the biopsies onto chorioallantoic chicken embryo membranes, a model which has never been used for this indication and which is one of the original features of our approach. These three concomitant approaches will allow us to increase our chances of obtaining stable upper urinary tract urothelial carcinoma lines to be used for the screening and identification of new treatments or new combinations of molecules that would benefit patients with upper urinary tract urothelial carcinomas, knowing that very few studies dedicated to this type of cancer have been conducted or published due to the rarity of the disease and the lack of existing models published on the subject of these particular tumors.

.

Inclusion Criteria:

• Patients treated consecutively at the Urology Andrology Department of Nîmes University Hospital for high grade carcinoma of the pelvis or renal ureter with an indication for total nephroureterectomy decided during a multidisciplinary meeting.
• Patient with a diagnosis of high-grade urothelial carcinoma of the pelvis or renal ureter confirmed by histology (biopsy, biopsy of the ureteroscopic) or by cytology with the presence of :
• High-grade disease on ureteroscopic biopsy OR ;
• High grade disease on urinary cytology AND infiltrating appearance of the renal pelvic wall / ureter on the scanner (the presence of hydronephrosis will be considered as pervasive by definition) with a negative cytoscopy.

Exclusion Criteria:

• Any patient who has undergone previous systemic treatment.

The study population consists of patients treated consecutively at the Urology Andrology department of Nîmes University Hospital for high-grade carcinomas of the pelvis or renal ureter for whom a total nephroureterectomy has been indicated during a multidisciplinary meeting. The tumor samples used for our study come from specimens removed surgically. Patients must not have undergone any prior systemic treatment.