2023 Head & Neck Cancer Conference Guide Book

Liquid biopsies – can they help us improve head
and neck cancer care? You can help us.
By Ben O’Leary, The Institute of Cancer Research and The Royal
Marsden Hospital, London, UK | ben.oleary@icr.ac.uk
One question we get asked a lot in the head and neck oncology clinic after patients
complete their radiotherapy is ‘how do we know if it’s going to come back’? It’s one of
the most important questions for people who have been through radiotherapy, but the
honest answer is that for any given individual we don’t know. It’s because we don’t know
that we see people so regularly even after they have completed their treatment, aiming to
catch any cancer recurrences as quickly as we can.
Those of us who work in
cancer research are trying
to find more accurate and
effective ways of detecting
cancer recurrence. One
promising technology has
been called ‘liquid biopsy’.
All of use have some of our
DNA floating in our blood,
which can we detected when
a blood sample is taken. A
relatively recent discovery is
that in people with cancer, a
small proportion of the DNA
in the blood can be found to
have originated form the
person’s cancer.
Liquid biopsies – Using blood tests to detect cancer.
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This means that it might be possible to develop a blood test designed to detect cancer
recurrence. The available evidence suggests that this could indeed be possible, although
at present difficult and expensive to do. We could potentially use a test like this to help
improve cancer detection in people who we have treated with radiotherapy.
Even though it is possible to develop liquid biopsy tests like this, what is not clear currently
is whether they are useful and provide benefit for patients. Detecting cancer recurrences
early could allow earlier treatment, which might improve how people feel or how long
they live. However, we don’t know this is the case, and it may be that such a test just
introduces additional burdens for patients in terms of inconvenience and anxiety, without
helping them feel better or live longer. It often feels logical that more medical testing
should produce better results for patients, but research has shown this is often not the
case. Given the expense and the complexity of these liquid biopsies, it is important to
properly understand if they can really help people before we start using them routinely.
The Swallows charity, working with colleagues in Edinburgh, has previously sent round a
survey asking people how they feel about some of these issues. Broadly, people liked the
idea of such a test, but felt it was important that the test be done with some treatment
in mind – not just to find out about recurrence, but to find out and then do something
about it.
We are now developing a clinical trial to see if using liquid biopsies can improve treatment
for people with head and neck cancer. We want to take blood tests for liquid biopsies
32 HEAD & NECK CANCER CONFERENCE 2023
from people after they have finished their radiotherapy for head and neck cancer and
test them for cancer recurrence, giving them treatment based on the result, rather than
waiting for the patient or their doctors to notice the cancer coming back.
An important part of clinical trials is comparison. If you want to try something new you
need to compare it to what you would have done normally to see if it is better. Without a
proper comparison you will never really know. The best way to get a fair comparison is to
randomly decide whether people get the usual treatment or the trial treatment – doctors
or patients can’t choose.
For our trial, this means randomly deciding whether patients and their doctors get the
liquid biopsy tests, or whether they don’t. At the end of the trial, we will see whether people
who, along with their doctors, were given the liquid biopsy information felt better and lived
longer, or whether they were just more inconvenienced and anxious, without living longer.
Communicating these ideas, along with the possible risks and benefits is hard to do well,
but so important to connect with people for whom this really matters – patients with head
and neck cancer and their families, friends, and carers. We would like your help so we can
do this better.
We work with an expert group of patients who we ask to help us with our research plans. They
flagged the following issues as important which I have tried to explain a bit about already:
1. Explaining why it was necessary to randomly decide whether a patient and their
team was informed or not of the liquid biopsy results.
2. Being clear that the trial would mean extra tests, which could be more
inconvenient and lead to worry about results.
3. If the trial showed the liquid biopsy test made a difference, being able to share
results with the people who had been randomly allocated the usual treatment.
We believe it is really important to get as many views on this trial as possible and we would
be very grateful for your help with this. It is harder than ever to get research funding for
clinical trials, and showing that a trial is supported by patients can make a real difference.
If you have any views on this trial, supportive or not, we would very much like to hear from
you, even if just to say you are supportive, or would be interested in hearing more. You can
email me on ben.oleary@icr.ac.uk.
Clinical trial design – People in the trial all have blood tests after they complete
their radiotherapy for head and neck cancer. Half of patients have their blood tests
analysed for cancer DNA and the patients and their doctors are told the results –
this is decided randomly. The other half have follow up as normal with their blood
tests only analysed when the trial finishes. Created with biorender.com.
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