Abscopal response and reversal of PD-1 resistance in a patient with nephroblastoma following radiofrequency ablation

Sheng Zhang^1*Mengyang Ju¹Mingjuan Sun²Wenfeng Li³

• ¹Shanghai Cancer Center, Fudan University, Shanghai, China
• ²Naval Medical University, Shanghai, China
• ³The Affiliated Hospital of Qingdao University, Qingdao, China

Nephroblastoma (Wilms tumor, WT) is an extremely rare and aggressive malignancy in adults with nonspecific clinical and imaging features. There is a lack of standard therapy for patients with progressive disease despite surgery and chemotherapy. Here, we report a unique case of a 27-year-old male with recurrent metastatic nephroblastoma who developed resistance to PD-1 inhibitor therapy and target therapy. Radiofrequency ablation (RFA) was then performed on the largest porta pulmonic lesion. Notably, three months post-ablation, a non-ablated pleural lesion exhibited a partial response. Continued combination therapy led to a complete response in the pleural lesion and regression of the ablated lesion, with symptom resolution. This case demonstrates a potential abscopal effect induced by RFA, where local treatment of one tumor site coincided with systemic regression of distant, untreated lesions and reversal of prior PD-1 inhibitor resistance.