Tumor-immune microenvironment revealed by Imaging Mass Cytometry in a metastatic sarcomatoid urothelial carcinoma with a prolonged response to pembrolizumab

Cold Spring Harb Mol Case Stud. 2022 Apr 28;8(3):a006151. doi: 10.1101/mcs.a006151. Print 2022 Apr.


Sarcomatoid urothelial carcinoma (SUC) is a rare subtype of urothelial carcinoma (UC) that typically presents at an advanced stage compared to more common variants of UC. Locally advanced and metastatic UC have a poor long-term survival following progression on first-line platinum-based chemotherapy. Antibodies directed against the programmed cell death 1 protein (PD-1) or its ligand (PD-L1) are now approved to be used in these scenarios. The need for reliable biomarkers for treatment stratification is still under research. Here, we present a novel case report of the first Imaging Mass Cytometry (IMC) analysis done in SUC to investigate the immune cell repertoire and PD-L1 expression in a patient who presented with metastatic SUC and experienced a prolonged response to the anti-PD1 immune checkpoint inhibitor pembrolizumab after progression on first-line chemotherapy. This case report provides an important platform for translating these findings to a larger cohort of UC and UC variants.

Keywords: neoplasm of the genitourinary tract.

Publication types

  • Case Reports
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents, Immunological* / therapeutic use
  • B7-H1 Antigen
  • Carcinoma, Transitional Cell* / drug therapy
  • Carcinoma, Transitional Cell* / pathology
  • Female
  • Humans
  • Image Cytometry
  • Male
  • Sarcoma* / drug therapy
  • Soft Tissue Neoplasms*
  • Tumor Microenvironment
  • Urinary Bladder Neoplasms* / drug therapy
  • Urinary Bladder Neoplasms* / pathology


  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents, Immunological
  • B7-H1 Antigen
  • pembrolizumab