Bladder cancer is one of those types of cancer that seems to fly under the radar screen of most folks.
It’s not that the disease is that uncommon. There were estimated to be 63,000 new cases of bladder cancer in the
Maybe the reason we are somewhat complacent about the bladder cancer is that for many people it is not a life threatening disease. It is frequently superficial, and requires repeated follow-up over a lifetime to look for recurrences which then require treatment.
It is a cancer that is associated with smoking, and over the past several years there has been an actual decrease in its incidence, perhaps related to decreased tobacco consumption. The decrease is most notable in African Americans. It is also a disease of the elderly, with increasing rates of incidence as one gets older. 10 year survival rates are close to 80%, although they are much lower (a bit less than 60%) for African Americans.
The problem for the typical patient with this cancer is the follow-up, which means cystoscopy (looking into the bladder with a long, thin lighted tube) with or without cytology (looking at cells obtained from a urine sample under the microscope to find evidence of cancer cells) every three months in the beginning, with increasing intervals over time.
There is no end point for this vigilant follow-up after the diagnosis has been made, and the initial treatment provided. Cystoscopy can be done in the doctor’s office, but it is not a pleasant experience (Not that it is bad as it used to be: today we have flexible, lighted tubes for the procedure. Years ago the tubes were rigid metal and very uncomfortable). Cytology, an examination for cancer cells under the microscope, is not as sensitive in disease detection for bladder cancer as it is in other situations such as the Pap test we all know about.
A recent report in the Journal of the American Medical Association (see note below regarding problems with the link) now suggests that another test, which has actually been around for a couple of years but has not found a place in the routine screening for bladder cancer, may help detect recurrent bladder cancer earlier, when the treatment options may be greater and the outcomes much improved.
The test, called BladderChek, measures a protein that is found in the urine of patients with bladder cancer. The protein, called NMP22, is a byproduct of cancer cell division and death. Up until now, it had been approved for use as a screening test for bladder cancer, especially in people at high risk. The advantage of the test is that it can be done in the doctor’s office off of a voided urine sample which is easy to obtain.
The problem with using this test in screening for bladder cancer is that there is no evidence that large scale screening programs for bladder cancer are effective or appropriate when used in the typical person.
Given the situation described above, where most of the cancers detected are either curable or very treatable over the long term, the value of a screening test for the average individual isn’t as clear as it is for diseases that can frequently lead to death such as colorectal cancer or breast cancer.
But when looking for recurrent disease, the situation is a different one. Now, there is a person at high risk for having a problem. The chance of a recurrence for even the patients with the earliest stage of bladder cancer is 50%, according to the authors in the JAMA article. They also comment that 10-20% of the patients followed up for bladder cancer will have a recurrent cancer found at their cystoscopy. That’s a pretty substantial number.
What the doctors did in this current study is combine the follow-up cystoscopy with the BladderChek test and a cytology exam. What they found was that the urine protein test significantly improved the chances the doctor would find the recurrent cancer if it was present, when compared to cytology. In fact, it increased the chances of finding the recurrence to about 99%. And, that information was available immediately in the doctors’ offices, as opposed to having to wait for a lab to send back a test result from the cytology examination.
It is important to note that the NMP22 test itself didn’t detect every cancer that was present. In fact, it was positive about 50% of the time the cancer had recurred. On the other hand, the cytology examination (examination of cells under a microscope by a pathologist or trained technician) was positive only 12% of the time.
It was the combination of the cystoscopy and the NMP22 test that resulted in the 99% figure noted above.
One of the important cautions in this study is that it was a “one time only” event for the patient. That is, the patients were only tested one time with the NMP22 test. It was not done on repeated visits over time. There were some instances in this study where the NMP22 test was positive, and the doctor did not see a cancer through the cystoscope.
That raises an intriguing question: what would happen if the test was done repeatedly over time, even with cystoscopy? Would the test pick up the recurrence before it could be seen? I suspect someone, somewhere is working to answer that question right now as I write this.
And, if we were able to pick up a recurrent cancer before it could be seen, would that mean that some of the more aggressive cancers could be treated more effectively, with a greater rate of long term survival? We know that the longer a recurrence of bladder cancer is present, the more difficult the situation for the patient. So, earlier detection of a recurrent bladder cancer translates into better treatment.
It’s too early to say what the impact of this paper is going to be on the treatment and follow-up of people with bladder cancer. But it does improve the odds that your doctor will be able to spot a recurrence earlier, and maybe improve the treatment options for you, as well as improve the quality of your life and the length of your years.
I suspect we are going to be hearing more about this test, and how doctors are going to use it in their everyday practices. But unlike the dogs that were able to smell bladder cancer in urine samples (discussed here last week), my hunch is that the benefit with this bladder test is going to be more accurate and more immediate.
Note: The link to the abstract of the JAMA article was not working, so I have provided the link to the JAMA homepage, where the article is listed on the table of contents.
For disclosure purposes, we (at the American Cancer Society) have had some contacts and discussions with representatives of Matritech over the past year regarding this test. This is not an uncommon situation for us, and many companies want us to know what they are doing. We have received no grants or other funds from Matritech, and had no prior knowledge of this study or its results until it was published. The topic of this blog was suggested by one of our staff who had no knowledge of those discussions.