Understanding Liquid Biopsy, with Nicholas Turner, MA, MRCP, PhD

March 5, 2018
Download MP3 (7.32 MB/7:51)

In this podcast, Professor Nicholas Turner discusses liquid biopsy, which is a procedure that uses blood to test for cancer in the body. 



ASCO: You’re listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the world’s leading professional organization for doctors that care for people with cancer.

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In this podcast, Professor Nicholas Turner discusses liquid biopsy, which is a procedure that uses blood to test for cancer in the body. Professor Turner is an Academic Consultant Medical Oncologist, Team Leader in the Breast Cancer Now Toby Robins Breast Cancer Research Centre at The Institute of Cancer Research in London, and Breast Team Lead for The Royal Marsden National Institute for Health Research Biomedical Research Centre.

ASCO would like to thank Professor Turner for discussing this topic.

Professor Turner: Hello. This is Dr. Nicholas Turner from The Royal Marsden Hospital in London, UK recording a podcast on the topic of liquid biopsies. And this is a podcast that accompanies a recent manuscript on this topic that's been released by the American Society of Clinical Oncology in collaboration with the College of American Pathologists.

Now what are liquid biopsies, and why is it an important topic for patients with cancer? We know that cancers release small parts of themselves into the blood and these parts of the cancer that are released into the blood are increasingly seen as a very valuable way of both detecting that cancer is present in the body, but, most importantly, a way of testing, biopsying for cancer that is, potentially, a much easier and simpler way of analyzing what is going on in the cancer than needing to do a surgical biopsy. In particular, we're talking about DNA, a cancer genetic material, which we can pick up in liquid biopsies. Now, this is small amounts of DNA, the genetic material of cancers, that are released into the blood, and then we're using liquid biopsies. We can analyze that DNA to work out what's gone wrong in the cancer, which mutations are present in the cancer, to guide therapy.

In theory, this is a better way, potentially, than analyzing biopsies because cancers can change as we treat them, and liquid biopsies can be conducted at the time the patient is going to be treated so that we can get a really accurate up-to-date analysis of what's going on in the cancer. But while there's a lot of excitement, we also need to be cautious about, really, what is the evidence of how we can use liquid biopsies in patients? What is the current way that they can be used in routine practice, at the moment, to help guide treatment? And what, still, is not ready there to be used routinely in the clinic, in the hospital? What, at the moment, is only really there for research and not ready to be put into the clinic yet?

So in this statement we made on behalf of ASCO and CAP, we looked to provide some guidance for physicians and scientists about where liquid biopsies are actually ready to be used into the clinic, and where, actually, at the moment, we still need more research before we actually put it into practice in the clinic. We provided guidance on how it's best to take the sample and which tests are potentially good to use.

Now, currently, there are some evidence that the liquid biopsy tests can be useful for patients who've got advanced metastatic cancer of particular types, and regulatory bodies have assessed liquid biopsies and confirmed there are biopsies that can be used for patients with lung cancer, as well as in Europe, those with colorectal cancer, to help guide their treatment, and those are now routinely used in the clinic. These specific assays help identify mutations that might be present in the cancer that would help identify the right treatment for those patients.

When the liquid biopsies are taken is really important. We know that they're best taken when the patient's got cancer that isn't being controlled by their previous treatment, and it's really important to take the samples at the right time, in the right way. We do know sometimes the liquid biopsies can miss the mutations that are there in the cancer. So if something's not picked up in the liquid biopsies, it still may be appropriate to consider having an actual tissue biopsy to test the cancer.

Now there's a lot of excitement about, potentially, other ways we could use liquid biopsies. In particular, there's a lot of excitement about could we use these liquid biopsies to screen for cancer in the first place? And what I mean by that is, could we use liquid biopsies in people who are completely healthy to look for signs of cancer and, potentially, pick up cancer earlier than we would do currently? There's also a lot of excitement, currently, about could we use liquid biopsies in patients who've been treated for cancer to work out whether they're cured or not? And both of these, if the tests came forward, could be really very important for patients and for people.

But, at the moment, there's not enough evidence to start using liquid biopsies either to look for cancer in people who are otherwise well, or in patients who've completed treatment for their cancer. And although there's a lot of excitement in these settings, it's very important to realize that, at the moment, there's not enough data to support using these in routine practice. We just don't know enough about whether the tests are good enough, accurate enough, in those settings yet.

So there's great excitement about what liquid biopsies can offer. They, potentially, without needing to have an invasive biopsy done or a surgical biopsy done provide very accurate information about what's going in cancer. We provide a statement that will help physicians work out when's the right time to use these tests and when the data doesn't currently support them. And I hope you, also, have found this podcast useful in understanding what we mean by liquid biopsies. Thank you.

ASCO: Thank you, Professor Turner. Learn more about types of biopsies at www.cancer.net. And for more expert interviews and stories from people living with cancer, visit the Cancer.Net Blog at www.cancer.net/blog.

Cancer.Net is supported by the Conquer Cancer Foundation of ASCO, which is working to create a world free from the fear of cancer by funding breakthrough research, sharing knowledge with physicians and patients worldwide, and supporting initiatives to ensure that all people have access to high-quality cancer care. Thank you for listening to this Cancer.Net Podcast.