Dr. Bukavina on implications of research on urine microbiome in patients with bladder cancer

In this video, Laura Bukavina, MD, MPH, discusses the implications of the recent European Urology Focus paper, “Global Meta-analysis of Urine Microbiome: Colonization of Polycyclic Aromatic Hydrocarbon–degrading Bacteria Among Bladder Cancer Patients.” Bukavina is a urologic oncology fellow at Fox Chase Cancer Center in Philadelphia, Pennsylvania.

Transcription:

This is a great background to go further. First, we found that we should not be using voided samples for bladder cancer research. If you're looking at urethral cancer sure, but if you're looking at bladder cancer research and the microbiome, you really should be just targeting catheterized samples. Second, once we cleaned out all the contamination, what we found is there are bacteria that are overly abundant in patients with bladder cancer. This type of bacteria are very unique, because they all have the ability to break down what's called polycyclic aromatic hydrocarbons, which is a chemical known to cause bladder cancer. It's present in a lot of factories and chemicals and cleaning supplies. But the number 1 exposure is actually from smoking. So people who are smokers, which is a lot of our patients with bladder cancer, they consistently have a much higher concentration of this chemical in their urine. And that has been previously established in research done before us. So by having this chronic exposure to smoking, or even secondhand exposure to smoking, then you sort of concentrate this chemical in your urine. Other bacteria are not able to use utilize it as food and it's actually toxic to them. But the certain type of bacteria that are over abundant in patients with bladder cancer, they are able to metabolize it and they're able to grow. And the thing is, when they break down this chemical, this pH chemical, it eventually gets broken down to something that's not carcinogenic. But in between step A and the final step of it being non carcinogenic, there are a lot of different intermediates that are actually more cancer causing than the initial pH. By having those bacteria continuously break down that pH we hypothesize, and this is hypothesis only, that it actually causes more carcinogenic compounds to be collected in the urine, which is why we continuously see that patients who continue to smoke have worse outcomes. They don't respond to chemotherapy, they have higher recurrence rates, they don't do better. And that's not just in bladder cancer; that's also in lung cancer and in a lot of tobacco causing cancers.

This transcription was edited for clarity.