Towards Individualization of Bladder Cancer Therapy: the Role of Microbiome in BCG Responsiveness Prediction

The microbiome, defined as a characteristic microbial community occupying a reasonably well-defined environment (e.g. gut microbiome), has been increasingly linked with different medical conditions and also with cancer. While there have been numerous investigations into the gut bacterial ecosystem, scientists have started to pay attention to the microbiome of the bladder only recently. Results from newest investigations support the understanding that the bladder possesses its own microbiome and it is not germ-free. Studying the relationship between bladder cancer and bladder and gut microbiome may lead to new insights which can be used to predict tumor behavior and/or response to therapy.

With this project, we aim to investigate the use of microbial fingerprint from the bladder and from the feces of bladder cancer patients in predicting therapy response prior to administration of Bacillus Calmette-Guerin or BCG. BCG causes the body's own immune system to attack the bladder cancer cells. It is applied directly into the bladder to prevent the cancer from growing and from regrowing. However, in around 40% of patients this treatment is not successful, BCG should be avoided, and other therapy strategies should be chosen. Unfortunately, there is no test available yet, which help to select patients who will benefit from the therapy before the therapy is started.

In this project we intend to determine the microbial fingerprint and to analyze if this fingerprint can be used as a selection tool. This tool may enable as us in the future to avoid application of BCG therapy for patient with a high risk of therapy failure and save time to start alternative therapy options and hopefully avoid tumor progression. Our second aim is to collect additional samples (blood, instrumented urine, bladder tissue, feces) to establish a local biobank for future microbiome projects.