Bladder Cancer Invading the Prostate and Penis and Multiple Bone Metastases Showing Significant Improvement after a Short-Term Pembrolizumab Therapy following Radiation and Gemcitabine and Cisplatin Therapy Leading to a Pathologically Complete Remission

A 65-year-old man was diagnosed with bladder cancer invading the prostate and penis and multiple bone metastases. He underwent palliative radiation (30 Gy/10 fr) through vertebral bones (Th3 and Th12-L5) and pelvic bones for pain control. The patient received pembrolizumab therapy after three courses of gemcitabine and cisplatin therapy. CT four weeks after starting pembrolizumab therapy showed that both the primary and metastatic lesions had notably reduced in size, and no new lesion was detected. He subsequently fell, resulting in a femoral neck pathological fracture, and underwent hemiarthroplasty. Pathological examination of the pathological fracture site revealed no residual tumor tissue.