Why Biomarkers Are a ‘Double-Edged Sword’ for Patients and Providers

Biomarkers can provide patients with cancer and their care teams with plenty of information. But, as an expert explained, they can also raise a big question: What’s to be done with all of this information?

“Are we replacing or augmenting, or are we improving upon our traditional findings? So many of us are familiar with things like the type of cancer and the stage of cancer, but as we have this extra information that's being built into it, how do we integrate this newer technology with the way that we've been doing things for decades?” asked Dr. Casey Cosgrove during the CURE® Educated Patient® Gynecologic Cancers Summit.

Cosgrove, who also served as the chair of the summit and is a member of the CURE® advisory board, is a gynecologic oncologist with The Ohio State University Comprehensive Cancer Center – James Cancer Hospital and Solove Research Institute in Columbus.

A biomarker, Cosgrove explained, is a molecule or entity found in a patient’s blood, body fluid, tumor or tissue, for example, that can signal abnormalities that can in turn be exploited or used to clinicians’ advantage when treating cancer.

Biomarkers can be prognostic, meaning what an individual’s prognosis looks like can be informed by the presence or absence of a biomarker, or they can be predictive and help provide understanding as to which treatments might have the best benefit for a patient, Cosgrove said. Biomarkers can be tested based on genetics, but more commonly, a tumor is tested to see what markers it may have to signal the best therapeutic options, Cosgrove told CURE in an interview.

One means of testing for biomarkers is through what is known as a liquid biopsy, a blood draw which uses a blood sample to check for circulating tumor DNA, or DNA that is shed by the tumor and can be found in the patient’s blood stream.

“There's been a lot of conversation about when we should be utilizing liquid biopsies, and there's been a lot of news about it. Particularly, there's newspapers and magazines, and people are really excited about it, because we might be able to avoid us having [to perform] certain biopsies with needles, and we could just do things with blood draws and get more up-to-date information quicker,” Cosgrove said during the summit. “Hypothetically, we could be testing this on anyone at any time, whether it's for detection of cancers or screening. We're really starting to work on figuring out how this biomarker can be integrated, not only for individual patients, but the population in general.

“We're still figuring out, are we ready for this and how we're going to interpret this data? And there's a lot of questions that go well beyond our conversation today, but we're talking about this, and this is really cool. As we get better technology, hopefully we can impact individual patients and take better care of our patients.”

Cosgrove, in his interview with CURE, described the amount of information that can be gleaned from biomarkers as “a double-edged sword.”

“Sometimes we have a biomarker that signals to us something — however, we don't have an intervention, or we haven't studied doing something different based off of that biomarker. And so we're left with knowing something about a tumor but not knowing how to handle it,” he said. “The other thing that can come about is sometimes we have a positive biomarker that just doesn't apply to a certain patient population.”

For an example of the former, Cosgrove said that among patients with endometrial cancer POLE mutations have been associated with positive outcomes, and researchers are now studying whether or not withholding treatment from patients with this mutation would result in better outcomes. “We tell them, ‘Hey, I think you have a better outcome potentially.’ However, we don't have enough data to really change the way that we're taking care of that patient today,” Cosgrove said.

On the other hand, while treatments known as PARP inhibitors have shown great benefit in patients with advanced-stage ovarian cancer with a BRCA mutation, it’s unknown if they will have any impact on patients with early-stage disease other than increasing toxicities.

“I think it's really challenging sometimes for our patients because they might have a biomarker that's positive; however, we don't have enough data, or they're not the right patient population that's been studied to alter the way that we take care of them, or treat [them] or alter their management,” Cosgrove said. “And so yes, it's great to get all this extra information, but with that extra information, we have to make sure that we're utilizing it appropriately in the way that's been studied in the past.”

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