If you've been researching prostate cancer, chances are good you've come across articles about molecular markers.
Below, we'll discuss:
• What molecular markers are
• Why molecular markers are relevant to prostate cancer patients in particular
• Our molecular markers protocol at Greater Boston Urology
As with all content on Greater Boston Urology's blog, the following information is educational in nature, not medical advice. Always talk to your physician about your specific health care questions and conditions.
[Editor's note: This article was reviewed and updated with additional links on 1/4/22.]
Living with a prostate cancer diagnosis: to treat or not to treat?
When a man receives a prostate cancer diagnosis today, he is faced with many decisions, the biggest being whether to aggressively treat the cancer or to opt for an active surveillance protocol.
This is not an easy decision since studies (and experience) over the last 15 years has revealed that not all types of prostate cancer warrant aggressive treatment. As many as one third of patients diagnosed with prostate cancer could forgo aggressive treatment and live the remainder of their lives without the prostate cancer affecting them (in other words, the patient dies from some other entity).
The challenge, of course, is answering the question that all patients have: "How do I know if my cancer is the type that doesn't need to be treated?"
How do prostate cancer biopsies add to the stress?
Some patients will see their PSA number continue to rise, yet when they have biopsies, they don't have prostate cancer. Anybody who's had a prostate biopsy knows it's an uncomfortable procedure physically (as well as psychologically). For patients who have a negative prostate biopsy, we want to diminish the possibility that they'll ever need another biopsy again.
So how do we do this? How can we help patients determine which "type" of prostate cancer they have and how do we diminish the need for repeated biopsies?
Through molecular marker studies.
What are molecular markers?
The National Cancer Institute defines molecular markers as such: "A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A molecular marker may be used to see how well the body responds to a treatment for a disease or condition. Also called biomarker and signature molecule."
How does Greater Boston Urology work with molecular markers for prostate cancer?
At Greater Boston Urology, we have a state-of-the-art in-house pathology laboratory. This allows us to provide services in clinical expertise that's unique in New England—services that can greatly help the prostate cancer patient.
In our molecular pathology program for prostate biopsies, we're doing two things. First, we're helping the patient who doesn't have cancer avoid future biopsies. Second, we're helping the patient who has prostate cancer pick the appropriate therapy based on the genetics of their individual cancer.
We can now customize a patient's therapy to his own individual genetics and the cancer's biology. This is an incredibly exciting development and extremely beneficial to our patients because we can give the patient better advice on therapy options.
How do molecular marker protocols help patients with a negative biopsy?
If a patient comes in and has a negative biopsy, a large percentage of these patients will undergo a second biopsy at some point. The problem with this is two-fold.
First, it puts a lot of emotional and physical stress on the patient and his family. Second, it potentially puts a lot of unnecessary expense into the total healthcare system.
However, thanks to molecular marker studies, we now have a test that helps us confirm that a negative biopsy is indeed negative. ConfirmMDx is the name of the test.
Here's how it works: in a genetic and molecular manner, this test evaluates the prostate tissue—tissue that our pathologist has already reviewed under the microscope and determined no cancer exists.
Sampling errors can occur with the traditional biopsy. Thanks to ConfirmMDx, we can now look for genetic markers.
Normal-appearing tissue might have a genetic marker indicating cancer does indeed exist. These markers are called methyl groups and they exist on the genetic material within the cells themselves.
ConfirmMDx is a commercially available test. If one of our patients at Greater Boston Urology has a negative biopsy, we can send out the tissue from the biopsy and test for the methyl markers. If the test comes back negative, the advantage is that we know 96% of those patients do not have clinically significant prostate cancer. In essence, it confirms the negative biopsy that we just did. Therefore, if that patient goes on to have a continually rising PSA, we're not immediately going to jump to re-biopsy that patient.
The other group that benefits? Patients who have no sign of cancer, but who don't have a normal biopsy. These areas of high-grade PIN (prostatic intraepithelial neoplasia) or sometimes just atypical glands within the prostate can be confounding to both the urologist and the patient.
Because there's no cancer there, we're reassured. However, the tissue still wasn't normal, which causes concern. ConfirmMDx, with its ability to investigate the methyl groups, can help us determine which patients we need to continue to follow closely—and which patients we can follow a little less closely (and which patients can delay having another biopsy).
The advantage of not repeating this biopsy is enormous to both the patients, the doctor, and the healthcare system in general because we'll lower the overall cost of care for this patient.
How do molecular marker tests help men diagnosed with prostate cancer?
For the patient who unfortunately is diagnosed with prostate cancer, he now has decisions to make. Many of the decisions are confusing and overwhelming because we're dealing with cancer. Nobody wants to do the wrong treatment, the wrong therapy, or make the wrong decision when dealing with something as significant as cancer.
However, as stated earlier, we know that not all prostate cancer needs to be treated. The challenge is being able to identify which prostate cancer needs aggressive treatment. Fortunately, there are genetic markers within the cells of the prostate tumor that can help us answer this question.
OncotypeDx is a test that looks at 17 different genes within the prostate cancer tumor. Assessing these genes will give us a score that allows us to decide whether a patient is at very low risk, low risk, intermediate risk, or high risk for their prostate cancer prognosis.
In high risk, the cancer has a high chance of spreading. For intermediate risk, within a 10-year period, this disease could spread or develop to a point that it will potentially spread. Obviously, patients in the intermediate and high-risk category will need treatment.
If patients, however, are in a very low-risk category and we've confirmed this based on their Gleason score and a low OncotypeDx score, then we can very comfortably assure these patients that they do not have a cancer that's likely to spread.
We can safely recommend active surveillance programs to these patients. Active surveillance programs minimize the side effects that patients are exposed to. Active surveillance also decreases their overall cost of care and it will give them the reassurance to know that in deciding not to actively treat the cancer, they are making the best decision for their overall healthcare.
An important note regarding "low risk": A slight percentage of patients labeled as "low risk" based on their microscopic Gleason score actually might have an intermediate disease.
The reason? We believe close to 30% of prostate biopsies actually under sample the amount of tumor that is present.
However, with the 17 genes that we're looking for, we can identify genetically that a patient has a greater risk of recurrence and rather than the low risk category, the patient may actually be in a higher risk group and thus require treatment. For these patients, we can now counsel—without doing another biopsy—to treat their cancer even though we're seeing what appears to be a low-risk cancer.
Bottom line: we now have genetic tools (in addition to traditional microscopic inspections of the prostate biopsy) that will allow us to not only stratify the person's risk but to individually cater their prostate cancer therapy based on their unique genetics.
Here's a video on OncotypeDX
How do molecular marker studies help those in the intermediate and high-risk categories?
For these patients, they microscopically either have a large volume of tumor in the prostate, meaning that of the traditional 12 cores we sampled, we're seeing cancer in either the majority or sometimes all of the cores we sampled. Or they have a very high Gleason score.
In other words, as we look at these cancers under the microscope, we know these are dangerous cancers, we know these patients have to be treated, and we know these patients are the patients that could possibly die of prostate cancer if we don't get their treatment strategy right.
Thankfully, we now have a genetic tool to help us counsel and advise patients in this groups as well.
At Greater Boston Urology, for our intermediate and high-risk patients, we're using a test called Decipher.
Decipher uses a 22-gene analysis of the prostate cancer cell themselves. Looking at these 22 genes, Decipher can tell us if this is a cancer that is likely to spread beyond the prostate—or that it already has likely spread beyond the prostate at the time of diagnosis.
If we see a high Decipher score with a high likelihood that the patient's disease has already spread beyond the prostate, we can then more properly counsel and educate that patient to look at treatment modalities that treat prostate cancer at the level of the whole body rather than just the prostate. This will avoid patients having side effects from therapies that we know are unlikely to work.
On the other hand, Decipher can also help us decide when local therapy might still work (meaning the prostate cancer hasn't spread beyond the prostate).
It's thrilling to be practicing medicine in a time where we can use the patient's genetic code from their individual tumor to make this decision. It's with these new advances in genetic testing that we're at the forefront of. This will only get better as time goes on and more tests become available.
How is GBU different from other practices when it comes to molecular marker protocols?
At Greater Boston Urology, we manage your biopsy AND we manage the pathology and total evaluation of your biopsy specimen. This is unique to our practice.
Thanks to molecular marker tests, such as ConfirmMDx, OncotypeDX, and Decipher, we now have tools that allow us to extract every bit of available information out of the tissue from the biopsy—information that will guide doctors and patients as they make decisions. This information will also reduce the need to re-biopsy patients.
This is an exciting time to practice medicine. Our molecular markers protocol provides a wonderful opportunity to treat every patient as his own unique person. In the end, this is going to lead to the best outcome for the patient, regardless as to whether they have their cancer treated or not treated. We're thrilled that we can provide this service to our patients.