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PD-1/PD-L1 Expression in dogs with Urothelial carcinoma (transitional cell carcinoma)

** Please note this study is closed/completed and no longer recruiting patients ** 


Urothelial carcinoma (UC; historically called transitional cell carcinoma) is a tumor that arises from the urinary bladder epithelium. Several therapeutic interventions have been attempted in dogs and humans, including NSAIDs, chemotherapy, and radiation therapy (alone or in combination). Despite aggressive therapies, most treatments only provide cessation of tumor growth for a short period.

The importance of the role of the immune system in cancer has become increasingly evident in the last decade in human medicine. In particular, a receptor complex called PD-1 and its ligand PD-L1, have been extensively studied in several cancers, including UC. Essentially, once bound, this complex creates a “stop” signal for the immune system, meaning that the cancer can evade immune detection and may continue to proliferate uncontrollably.

The research behind PD-1 and PD-L1 in urothelial carcinoma, has allowed for progress in therapies via monoclonal antibodies in people. However, the role of PD-1 and PD-L1 in veterinary oncology remains to be elucidated, especially with urothelial carcinoma.

Therefore, the goal of this study is to determine if peripheral white blood cells, as well as urine lymphocytes harbor PD-1 in dogs with UC, compared to control dog populations. We also plan to evaluate cytokine expression that affects PD-1 in dogs with UC compared to controls. If PD-1 is present, this may become a target for future drug development in dogs.

Inclusion criteria:  

  • Dogs of any breed or age under 25kg
  • A diagnosis of urinary bladder urothelial carcinoma
  • No prior anti-tumor treatment if possible (NSAIDs included)
  • No prior immunomodulatory medication or vaccination within the past month

Samples required:  

  • Blood sampling (6mL) once
  • Urine sampling (3-6 mL) once

Client Compensation:              

  • No cost to participate    


  • Dr. Samuel Hocker (PI)
  • Dr. Chris Pinard
  • Dr. Anthony Mutsaers
  • Dr. Byram Bridle
  • Dr. Paul Woods


Vicky Sabine (PhD), Clinical Research Coordinator

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