Robert Svatek, MD, Urological Oncologist at UT Health San Antonio talks about battling bladder cancer with Gemcitabine.
Interview conducted by Ivanhoe Broadcast News in July 2018.
So you took a medication that has traditionally been used against other cancers and now you’re experimenting as to whether or not it’s going to work on bladder cancer?
Dr. Svatek: That’s right, and we used it in a kind of unique form. We put it into the bladder immediately after removing a bladder tumor.
How do you get it down in to the bladder? And the medicine is?
Dr. Svatek: Gemcitabine. We instill it into the bladder immediately after removing a bladder tumor. So there’s no cutting or needles. We use a natural orifice into the bladder and after we scrape the tumor out, we put a catheter through that orifice and instill the medication. It sits in the bladder for an hour and then it’s removed and the patient goes home.
What is it in there to do?
Dr. Svatek: The problem is that after you scrape a tumor out, there are small little tumor cells that can implant in other sites of the bladder and grow in to tumors. This medication kills those floating cells and any cells that may be trying to develop in to cancer. It basically prevents these tumors from growing and as a result, patients have fewer tumors come back after they’ve been undergoing the procedure.
So previously, have you had any other medication to do the cleanup work after you did surgery?
Dr. Svatek: Yeah. The idea of putting chemotherapy into the bladder is not particularly new and we’ve used lots of different medications to do this. However, the medication that is most commonly used is toxic and has some considerable side effects. What’s really unique about this new medication is that it’s safe.
Take that one back to the top.
Dr. Svatek: Sure. So the idea of using chemotherapy and instilling it into the bladder is not new. We’ve been using different medications to do that for several years. What’s different about this medication is it’s safer than the other medications that we’ve used in the past.
What is this primarily used for?
Dr. Svatek: Gemcitabine is used mainly for chemotherapy given into the bloodstream and for more advanced type of cancers. So this is a unique way to use it, by instilling it into the bladder.
What gave you the idea for this particular medication and has anybody thought of this before?
Dr. Svatek: I don’t know the answer to that.
Well, just the first part.
Dr. Svatek: This medication is available and it’s not undergone shortages. One of the issues with regards to the other medications is that they’ve had national shortages. This drug is relatively inexpensive and relatively safe. So I think that’s the idea, plus we know that it works in bladder cancer, at least in more advanced disease sites.
So bladder cancer is dangerous because…?
Dr. Svatek: Number one, it has a very high relapse rate. Meaning if you take the tumor out, the chances of it coming back are more than 50% and that contributes to bladder cancer being one of the highest costs per patient of all tumor types. Patients require multiple office visits, multiple procedures, and multiple different tests because of this. Any time you do procedures there’s risk involved with that. There is a chance for these tumors to develop in to more aggressive tumors where the bladder actually has to be removed, or they could spread to other parts of the body in what we call metastasis, which is less responsive to therapy and harder to cure.
So traditional chemotherapy that’s been used after you surgically did the operation and you put chemotherapy in there; it’s not working as well as this particular drug?
Dr. Svatek: First off, these are tumors that are confined to the bladder. These patients do not have metastatic disease. These are tumors that are what we call noninvasive, or non-muscle invasive. So the tumors themselves are not really a threat at this time to the patients. So they don’t get chemotherapy that’s given into the blood. That’s not the management.
Start again.
Dr. Svatek: If these patients have tumors that are confined to the bladder, they’re not metastatic. So they don’t get chemotherapy that’s given in the bloodstream. They get the tumors removed surgically and then they may get some type of medication into the bladder to help prevent the tumor from coming back.
How is this different than from what you used in the past?
Dr. Svatek: It’s safer and it’s cheaper, that’s the bottom line. There are other medications out there, such as other chemotherapies, but they’re toxic. This one is less toxic and it’s cheaper. It also appears to be effective, perhaps as effective or more effective than other drugs out there.
So in addition to the expense, really what you’re trying to do is save the patient the struggle, correct?
Dr. Svatek: That’s right, and save the patient from having to develop another tumor. This drug reduces the risk of tumors coming back by up to 47%, which is a large effect on the relapse rate.
Do you excise the tumor before putting this drug in?
Dr. Svatek: Yes, we take the tumor out. We scrape the tumor out and then the drug is put in.
The drug actually goes in through this catheter hole. How does it end up where it’s supposed to end up? Are you controlling the catheter at the other end?
Dr. Svatek: The catheter goes into the bladder and then the medication is put into the bladder. There’s just one route into the bladder. There are no other pathways, so it just goes into the bladder.
What is physically happening when you put the medication in there?
Dr. Svatek: The chemotherapy kills the cells that are floating around. In terms of how the chemotherapy works, how it kill cells: it’s complicated. But different chemotherapies work for different mechanisms. This one interferes with the replication of the tumor cell.
Explain to us again about how toxins impact the kidney and the elimination process.
Dr. Svatek: Bladder cancer is caused by exposure to environmental toxins. What we call carcinogens, or things that cause cancer. One of the most common toxins is tobacco smoke, but there are lots of other toxins in the environment, such as dyes or chemicals. Exposure to these different things can cause the toxin to get in the bloodstream which is then filtered out by the kidneys. The toxin gets into the urine and then the bladder, which serves as a reservoir for urine, is exposed to continuous amounts of toxins. That’s why the bladder is particularly susceptible to developing cancer from these environmental type of toxins.
So it’s just basic plumbing because it’s the last thing in the body to hang onto it and get rid of it.
Dr. Svatek: That’s right and it’s a reservoir because the other structures that hold urine hold it for a very temporary amount of time, whereas the bladder will hold it for a long period of time. So it’s partly that it’s the last exit strategy, but it’s also that it is a reservoir with longer exposure to the toxins.
Do you have any idea what other toxins we’re exposed to in addition to tobacco and dyes? Can it be water bottles in the car, for example?
Dr. Svatek: We’ve studied lots of different things and there have been tons of different theories. These are not easy to prove. For example, we can study them in a mouse model or an animal model, but definitively proving it in humans is hard. If you look back, people and scientists tried to convince the public about the harms of tobacco use way before we ever acknowledged that it actually happened. So it’s getting definitive proof that this is actually the cause that’s very difficult. But there are many different speculations as far as things in the water, habits that we have acquired, and new things that we have done because of technology that may be causing this.
Tell us where you are in the trial and research process.
Dr. Svatek: The trial was initiated many years ago. When I came here in 2010 it was just starting. The trial is now completed, but then after the trial we had to follow the patients for several years to see the effects of the trial. We recently did the analysis on the trial and presented the data in the Fall of 2018. As of now, the trial’s results have made a difference because we’re using this new drug routinely in our practice and I’m sure lots of other urologists are doing it as well.
Do you have anecdotal information or statistical information to prove that?
Dr. Svatek: The research findings are that we reduce the risk of cancer relapse by about 47% in the low grade tumor population, which is what this targeted. Patients getting the control drug had about a 53% rate of cancer return compared to 35% for the drug. That translates into about a 47% reduction in the risk of relapse, over a long 40 year period of time.
Is there a group of people more apt to get bladder cancer?
Dr. Svatek: Those that are exposed to environmental carcinogens, such as tobacco users, or other people that have been exposed to industrial carcinogens.
So you don’t see really it in kids?
Dr. Svatek: No, that’s a good point. It’s a disease of patients generally in their sixties and seventies because that’s the amount of exposure time the cancer needs to develop
When you see a tumor in someone’s bladder, what’s the general prognosis? Because when you hear pancreatic, that’s a death sentence, but what about bladder cancer?
Dr. Svatek: There are two different types. There’s a very aggressive type similar to pancreatic that’s very deadly and can grow very fast. Then there’s the type that is not as bad and can often be cured with appropriate management. That type can be scrapped out and you can save the bladder. That’s the type that this drug is particularly targeting. This type that is not deadly is problematic because it recurs so frequently. So while it’s not deadly, it can be a huge burden to our society because of the number of procedures that patients undergo because of the side effects associated with procedures and the time and resource commitment to monitor the patient.
END OF INTERVIEW
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