Bladder irrigation with the BCG vaccine in patients with bladder cancer ensures a more active immune system. This ‘training’ of the immune system may also increase the effectiveness of bladder cancer treatment. This has emerged from research by a team of national and international researchers from Radboudumc, Erasmus MC, Murdoch Children’s Research Institute and IKNL.
More active immune system through BCG bladder irrigation
We know that vaccination with the BCG vaccine against tuberculosis ‘trains’ the innate immune system. Through this training, also called ‘trained immunity’, immune cells of the immune system can respond faster and more powerfully. BCG vaccination therefore also offers protection against other respiratory infections.
Whether bladder irrigation with BCG as a treatment for bladder cancer also leads to trained immunity was unknown. A team of national and international researchers investigated this by collecting bodily samples and analyzing data in four bladder cancer studies; Tribute, BlaZIB, UroLife and the Nijmegen Bladder Cancer Study (NBCS). IKNL is closely involved in the last three studies.
The main results of the research
In the Tribute study, blood and urine samples were collected from 19 patients with non-invasive bladder cancer during the first year of BCG treatment. Laboratory experiments with immune cells isolated from the blood showed that immune cells were indeed more active after BCG bladder irrigation. This increased activity persisted for weeks to months after the last BCG flush.
Analyzing data from 678 patients from the BlaZIB and UroLife studies, the researchers found that treatment with BCG reduced the risk of a respiratory infection by 37%. These results show that trained immunity does indeed develop with bladder irrigations containing BCG.
In 215 BCG-treated patients of the NBCS study, the relationship between the degree of training and the outcome of BCG treatment was then investigated by means of genetic research. This showed that there may be a link between genetic variants that influence the degree of training by BCG and the recurrence of bladder cancer after BCG treatment.
Repeatedly flushing the bladder with BCG vaccine leads to a long-term training of the innate immune system. This training may reduce the risk of bladder tumor recurrence.
dr. go. Sita Vermeulen
Further research into improving bladder cancer treatment
The demonstrated training of the immune system may be relevant to the clinical outcome of BCG therapy. It is important to investigate in further research how we can use this knowledge to improve the treatment of patients with bladder cancer. For example, laboratory experiments can investigate whether the use of other substances that provide a strong training, possibly in combination with BCG, gives a better clinical result.
Bron
This research is published in the Journal for ImmunoTherapy of Cancer: Intravesical BCG in patients with non-muscle invasive bladder cancer induces trained immunity and decreases respiratory infections. Jelmer H. van Puffelen, Boris Novakovic, Liesbeth van Emst, Denise Kooper, Tahlita CM Zuiverloon, Ursula TH Oldenhof, J. Alfred Witjes, Tessel E. Galesloot, Alina Vrieling, Katja KH Aben, Lambertus ALM Kiemeney, Egbert Oosterwijk, Mihai G Netea, Joost L. Boormans, Antoine G. van der Heijden, Leo AB Joosten, Sita H. Vermeulen.
More information
You will find more information about this study in this article by Radboudumc. Do you have a question? Please contact Dr. Katja Aben, senior researcher at IKNL or adviser on genitourinary cancer and cancer & life Dr. Vera Atema.