This entry is part 5 of 23 in the series Science Surgery
Our Science Surgery series answers your cancer science questions.
If you have a question that you’d like us to answer, send it to us using the email address at the bottom of this post.
Toyin asked: “Do you think personalised therapy will soon be the norm in the management of cancer? Do you think that the standard practice of one-size-treatment-fits-all doesn’t work and is obsolete?”
Medicine has been becoming more personal for some time now. This is partly down to a growing understanding of diseases, including cancer. And with new technology, scientists and doctors can study a person’s own, individual cancer.
With this information they hope to identify the best proverbial spanner to stick in its works. That’s the goal of personalised medicine.
Whether this is likely to become the go-to way of treating cancer is a question best answered by those working in this rapidly growing field. That’s why we spoke to a number of Cancer Research UK-funded experts to see how they would answer Toyin’s question.
Professor Adele Fielding, University College London
“Ironically, the term ‘personalised therapy’ can mean something different to everyone,” says Fielding. “As a broad definition, it is a treatment approach specific to the individual and their own genes.
“Conceptually, personalised therapy predicts that treatment for cancer could become significantly more effective and less toxic for the patient if it were more ‘tailored’ to the genetics of their cancer.
Cancer treatment will become increasingly personalised by default, as we learn more and more.
– Prof Adele Fielding
“But where we lack new treatments that can target a patient’s specific cancer, personalised therapy simply means putting our best foot forward in choosing the most appropriate treatment from lots of existing drugs.”
But in order to reach its potential, Fielding points out that there are a number of obstacles that need to be overcome.
“Doctors and nurses would require access to sophisticated diagnostic techniques, and a huge increase in the range of effective and approved treatments” she says. “We’d also need large-scale clinical trial data which connects those hundreds of new therapies with certain tumour characteristics, or ‘biomarkers’, to assign them to individuals in a personal fashion.
“We will continue to refine our approach to cancer treatment. It will become increasingly personalised by default, as we learn more and more.”
Professor Andrew Biankin, Glasgow University
“Personalised medicine is not a new paradigm or a revolution, it’s simply the natural evolution of healthcare,” says Biankin. “What’s changed is our ability to measure differences in the diseases that people develop, and the realisation that these differences matter.
“For many years we’ve assumed that because a disease looks similar under the microscope, it shares similar molecular features, however this has proven to be untrue. Understanding the molecular basis of cancer can start to explain why there are so many differences in how diseases affect people, and how differently they respond to treatment.”
Personalised medicine… is a natural evolution of how we study and treat disease.
Prof Andrew Biankin
Biankin points out that personalised medicine has been around for a long time, highlighting the important example of tamoxifen, a hormone therapy for breast cancer that was developed in the ‘60s. This drug, and other similar hormone therapies developed afterwards, targets the oestrogen-sensing molecule on the surface of cells, called the oestrogen receptor.
But Biankin says that research is finding that cancers are more complex than previously imagined, which raises challenges for personalised medicine.
“Some cancers have a common target that drugs might be able to be developed against, like the oestrogen receptor in breast cancer. But personalised medicine is becoming difficult in other cancers where there are few of these targets, and our health systems and clinical trial networks aren’t built to accommodate these challenges.
“Personalised medicine is a reality. It is the way forward. It is a natural evolution of how we study disease and how we treat disease, and we need to understand and change our systems in order to respond to this new knowledge.”
— Cancer Research UK (@CR_UK) November 14, 2017
Professor Kevin Brindle, University of Cambridge
“A better understanding of tumour biology has led to the development of targeted therapies,” says Brindle, adding that these drugs are designed to interfere with molecules used by tumour cells to survive and grow.
“The introduction of these drugs, however, has shown that patients’ cancers can vary widely in their responses.”
Patients’ cancers can vary widely in their responses [to targeted therapies].
Prof Kevin Brindle
Brindle says that better techniques are needed to detect these responses in real-time.
He believes that molecular imaging – a technique that allows researchers to see inside tumours using scans and measure the processes happening inside cells – is likely to play an increasingly important role in this.
The techniques could predict and detect “early responses to these drugs and thus guide treatment in individual patients, allowing rapid selection of the most effective treatment”, he says.
Dr Alastair Greystoke, Newcastle University
“Personalised therapy is already the norm for some cancers. Lung cancer is the best example of this, but other cancers are following,” says Greystoke.
“There are now 4 different sub-types of lung cancer where we can target the genetic fault driving the cancer with tablets that are more effective and have fewer side-effects than chemotherapy. Whilst these make up a relatively small number of patients, there are international efforts to find more lung cancer patients we can treat in this manner (for example through the UK’s National Lung Matrix study and the US Lung MAP study). Similar efforts are underway in a number of other cancers too.”
Greystoke also highlights the potential of ‘liquid biopsies’, blood tests which fish out fragments of tumour DNA or cancer cells and analyse them. These are being trialled in a large number of studies across the globe, and could one day allow researchers to track and target how a person’s cancer changes over time and in response to treatment.
To just treat a cancer on the basis of where it arose in the body is an oversimplification.
Dr Alastair Greystoke
“The other way we are personalising therapy is drugs to help the immune system attack the cancer,” says Greystoke. “It is clear that some cancers respond much better to these drugs than others, so with immunotherapies – such as nivolumab and pembrolizumab – some patients are alive and well 5 years after their advanced lung cancer was diagnosed.”
Researchers now need to understand how to predict if immunotherapy will work, while also finding ways to make it work for more patients.
“To just treat a cancer on the basis of where it arose in the body is an oversimplification,” says Greystoke. “Cancer cells are immensely complex, and are trying to survive against the efforts of our immune system and drugs designed to kill them.
“Advances in science mean we know far more about this complexity and how to target it. We now need to adjust our treatments and the way we treat cancers in light of this, if we are to improve the outcomes for our patients.”
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