Exceptional Response To Immunotherapy In Association With Radiotherapy In Patient With Breast Metastasis From Urothelial Carcinoma: A Case Report

Most common sites of metastasis of urothelial carcinoma (UC) are lungs, liver, lymph nodes and bone. Pembrolizumab, a humanized monoclonal antibody directed against programmed cell death protein-1 (PD-1), represents an effective second-line therapy for advanced UC. Radiotherapy has been shown to induce a mechanism of immunogenic cell death (ICD) resulting in immune memory and advantageous systemic effects. We present the first case of breast metastasis (BM) from a UC described in literature who had an exceptional response to second line therapy with pembrolizumab in association with radiotherapy, showing the efficacy of combining immunotherapy and radiotherapy even in patients with atypical metastatic sites.