What is biomarker testing and how does it guide ovarian cancer care? Dr. Kevin Elias explains how analyzing specific genes and tumor markers—such as BRCA mutations and other molecular changes—helps personalize ovarian cancer treatment decisions and identify targeted therapy options.
Dr. Kevin Elias is a gynecologic oncologist and serves as the Lilli and Seth Harris Endowed Chair for Ovarian Cancer Research at the Cleveland Clinic, where he holds academic appointments in Gynecologic Oncology, Obstetrics and Gynecology, and Biomedical Engineering. Learn more about Dr. Elias.
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Transcript
Katherine Banwell:
Could you explain for our audience what biomarker testing is?
Dr. Kevin Elias:
Biomarkers are any type of additional laboratory testing, which helps guide diagnosis or therapy. So, biomarkers include special stains that we might do on the tissue itself for deciding what type of ovarian cancer it is. It would also include genetic analysis of the tissue, such as the determination whether the tumor is HR-proficient or deficient to guide therapy. There are some biomarkers that we use in order to help us determine the likelihood that somebody has ovarian cancer.
So, for instance, when we get blood tests prior to surgery, like a CA-125 test or other blood-based biomarker tests, like an OVA1 test, which involves multiple protein biomarkers, that can help us predict what the likelihood of finding cancer is at the time of surgery. But they’re not diagnostic. They’re simply a guide for helping a clinician make a decision about what they expect to find.
Katherine Banwell:
You’ve touched upon this, but how do results impact care and treatment options?
Dr. Kevin Elias:
When it comes to the type of ovarian cancer and the genetic makeup of it, it will guide what recommendations are made as far as genetic testing goes. It’ll also make decisions as far as what types of therapies would be most appropriate for a patient. Particularly as new treatments for ovarian cancer have been developed over the last couple of years, increasingly we’re seeing targeted therapy where the medication is specifically linked to a marker that’s expressed by some tumors, but not others.
And so, we would really want to know if a patient expresses an appropriate marker for targeted therapy. The HR-proficient versus deficient status is the first one of those biomarker-driven therapies that we’ve incorporated in ovarian cancer practice. But there are new biomarkers coming out, such as folate receptor expression, which are being used to guide treatment, not only in the later setting, like the recurrent setting, but increasingly in the upfront and maintenance settings with the first round of therapy.
Katherine Banwell:
What questions should patients be asking about their test results?
Dr. Kevin Elias:
They should be asking, with an initial diagnosis, whether they’re a candidate for upfront surgery or not. We do know that tumors that are amenable to primary surgical removal generally have a better prognosis than tumors that require chemotherapy to shrink them somewhat before surgery becomes an option. And so, consider having a surgical evaluation. In fact, many patients don’t see a surgeon with their initial diagnosis.
They may only see a medical oncologist. So, it’s important to have a consultation with a gynecologic oncology surgeon to determine whether or not someone’s a candidate for primary surgery. If they’re not a candidate for primary surgery, they should ask whether they’re a candidate for what’s known as HIPEC therapy, which is heated intraperitoneal chemotherapy.
That’s a special treatment which is offered after several rounds of chemotherapy, but it’s actually given in the operating room during the surgery to remove any residual disease. It’s only offered typically in specialized centers, but one should ask if HIPEC is available locally because it has been shown to help reduce the risk of cancer recurrence after completion of treatment.
Katherine Banwell:
That’s good to know. What is the difference between tumor testing versus inherited genetic testing?
Dr. Kevin Elias:
So, we think about two different genetic elements of a tumor. One part of that is the genetics that is common to every other part of the body, so the genes that we’re born with. And we sometimes refer to that as germline genetic testing or familial genetic testing.
Those would be genes like the genes BRCA1 and BRCA2 that might confer a lifelong risk of ovarian cancer, as well as other cancer types, for instance, breast cancer. There’s also the fact that every tumor cell has acquired genetic alterations that make it different from normal cells in the body. And so, we sometimes refer to this as tumor testing or somatic genetic testing, where we’re looking for genetic features that are unique to the tumor, but may not be shared by other cells in the body.
And there are therapies that could be used for mutations that are present in either the germline context or the somatic context. However, if we were talking about other cancers in the same individual or familial cancer risk, that would only apply to the germline testing scenario.