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

Abstract

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.

Figure 1

CT findings before treatments showed an invasive bladder tumor with (a) bilateral hydroureters (arrows) and (b) osteolytic metastasis (arrow). Pathological findings of needle biopsy of bladder and prostate lesions revealed luminal-type urothelial carcinoma ((c) hematoxylin and eosin), (d) androgen receptor-negative, (e) GATA3-positive, (f) CK20-positive, and (g) PD-L1 negative. There were almost no tumor-infiltrating lymphocytes within the tumor tissue ((g) circles). Internal control histiocytes are PD-L1 positive ((g) arrow).

Figure 2

CT findings four weeks after starting pembrolizumab therapy revealed a significant reduction in the size of the primary lesion (a), as well as a decrease in osteolytic lesions at the bone metastatic sites with a shift towards osteoblastic change (b, arrow).

Figure 3

Pathological findings of fracture lesion revealed no residual cancer tissue with osteoblastic change.