Upper tract urothelial carcinoma (UTUC) in Taiwan exhibits unique epidemiological and clinical characteristics compared to global trends. The disease is notably more prevalent in Taiwan, with an incidence rate of approximately 3.14–3.41 cases per 100,000 people, significantly higher than the global average of 1–2 cases per 100,000. Avelumab is an immune checkpoint inhibitor that targets programmed death-ligand 1 (PD-L1), primarily used in the treatment of advanced urothelial carcinoma (UC) and muscle-invasive bladder cancer (MIBC). This therapy has gained attention for its role in maintenance treatment following first-line chemotherapy, demonstrating significant benefits in overall survival (OS) and progression-free survival (PFS). However, in JAVELIN trial, it did not specifically analyze the subgroup of patients with clinically node-positive, non-metastatic disease. Therefore, the potential utility of avelumab maintenance therapy in this group still remains unclear.

The cases presented here illustrating a node-positive UTUC diagnosed at our hospital at April 2022 with upfront cisplatin-based chemotherapy after radical nephroureterectomy, followed by avelumab as maintenance therapy for over two years.

This case is a 74-year-old female with a past medical history of chronic hepatitis B, type 2 diabetes mellitus, and hyperlipidemia. Her initial presentation occurred with left flank soreness and hematuria for weeks. Following this presentation, in April 2022, the patient underwent a left ureteroscopy (URS) biopsy which revealed non-invasive papillary urothelial carcinoma, high grade. Subsequent imaging with CT scan in April 2022 showed an enhanced soft tissue lesion (2.1* 6.2 cm) in the left upper and middle third ureter with hydroureter and hydronephrosis, and enlarged lymphadenopathy along the left common iliac artery (3.6 cm). A whole-body bone scan performed in May 2022 showed no evidence of metastatic bone lesion. In May 2022, the patient underwent laparoscopic left nephroureterectomy with bladder cuff resection and lymph node dissection. The pathology report showed left invasive urothelial carcinoma, high grade, and left external iliac lymph node metastasis ＞2 cm, with pathological stage of T2N2. Between June and October 2022, the patient received four cycles of chemotherapy with Gemcitabine plus Cisplatin. A follow-up CT image in November 2022 showed no definite recurrence. Subsequently, around November 2022, the patient started maintenance therapy with Avelumab administered every two weeks. Recent CT scan in September 2024 showed no definite recurrence. The patient has now been on Avelumab therapy for over two years and remains in complete remission. During the treatment, no immune-related adverse events were observed, and the patient’s quality of life was maintained.

The case demonstrated a positive response and long-lasting remission with avelumab treatment, for advanced UC that has not progressed with first-line platinum-based chemotherapy.