INVESTIGATIVE UROLOGY

Immune mechanisms in bacillus Calmette-Guerin immunotherapy for superficial bladder cancer
Böhle A., Brandau S
From the HELIOS Agnes Karll Hospital (AB), Bad Schwartau and Division of Immunotherapy, Department of Immunology, Research Center Borstel (SB), Borstel, Germany
J Urol. 2003; 170: 964-9

• Purpose: Of all medical disciplines it is exclusively in urology in which immunotherapy for cancer has an established position today with intravesical bacillus Calmette-Guerin (BCG) against superficial bladder carcinoma recurrences. BCG is regarded as the most successful immunotherapy to date. However, the mode of action has not yet been fully elucidated. We provide a thorough overview of this complex field of research.
• Materials and Methods: Rather than simply reporting all experimental data available for better understanding the involved immune mechanisms, we chose to provide comprehensively only information supported by several independent pathways of evidence.
• Results: Major findings made during the last few years include systematic analyses of patient material, detailed in vitro studies and investigations in animal models, which have led to a substantially greater understanding of the mechanisms involved.
• Conclusions: The efficacy of BCG is based on a complex and long lasting local immune activation. The bladder as a confined compartment, in which high local concentrations of the immunotherapy agent and effective recruitment of immune cells can be achieved, serves as an ideal target organ for this type of immunotherapy approach.
  
• Editorial Comment
  Intravesical BCG against superficial bladder carcinoma recurrences is regarded as the most successful immunotherapy to date. However, the mode of action has not been fully elucidated yet. Since the immuno-activating properties of BCG were discovered, investigations have been carried out to ascertain the functional mechanism. All investigations to date have shown that not one single functional mechanism, but a whole series of immunological phenomena are involved.
  Doctors Boehle and Brandau, world leading researchers on BCG in superficial bladder carcinoma, present in this article the most recent knowledge on this form of immunotherapy. They describe the major findings made during the last few years when systematic analyses of patient material, detailed in vitro studies and investigations on animal models have led to a substantially greater understanding of the mechanisms involved. This review explains why BCG therapy is currently considered the most successful immunotherapy of solid tumors, and therefore, must be read by every urologist interested in bladder cancer.

Dr. Francisco J.B. Sampaio
Full-Professor and Chief, Urogenital Research Unit
State University of Rio de Janeiro
Rio de Janeiro, Brazil