Nephron-sparing Treatment of Tislelizumab + Nab-Paclitaxel for Renal Pelvic Cancer

This study is designed as an open-label, single-arm, single-center, phase II clinical trial, aiming to evaluate the efficacy of nephron-sparing treatment combining Tislelizumab and Nab-Paclitaxel for HER-2 expressing renal pelvic cancer (RPC) . Patients enrolled will receive 2-3 cycles of Tislelizumab in combination with Nab-Paclitaxel every 3 weeks and then undergo evaluation. Patients who achieve all of the following criteria of "well response and tolerance" will receive further maintenance treatment: (1)The patient achieves a complete response (CR) or partial response (PR) according to the RECIST 1.1 criteria, indicating that the tumor is well-controlled. (2) If the patient has residual lesions, it should be confirmed by the clinical physician that these lesions can be eliminated through laser ablation via ureteroscopy. (3)The patient has not experienced any treatment-related adverse events (TRAEs) that warrant discontinuation of therapy during systemic treatment. (4)The patient is willing to undergo further maintenance therapy. If the patient meets all the criteria above, ureteroscopic biopsy should be performed. If residual lesions are detected under the ureteroscope, endoscopic intervention (e.g., laser ablation, cryoablation) should be carried out simultaneously to eliminate these residual lesions. Patients who meet the above criteria will proceed with no less than 2 cycles of maintenance systemic therapy (Tislelizumab + Nab-Paclitaxel). Patients who do not meet the criteria will be excluded from the study and are recommended to undergo salvage radical nephroureterectomy (RNU) as soon as possible. One-year Nephron-Sparing Survival (1 year-NSS): Defined as the absence of surgical indications for nephrectomy due to progression or recurrence of upper urinary tract urothelial carcinoma, distant metastasis caused by the primary upper urinary tract tumor, or death from any cause within 1 year from the initiation of treatment. Treatment-related adverse events (TRAE