In our new blog series we're taking a close look at breast cancer treatments. For part one we spoke to Professor Rob Stein about chemotherapy.
When it comes to finding better ways to treat breast cancer, it’s easy to think of the brand new ‘targeted’ drugs as the treatments of tomorrow. But there’s plenty of research into improving ‘cornerstone’ treatments – namely surgery, chemotherapy, and radiotherapy – that have been the basis of breast cancer treatment for decades, or even centuries.
Over a series of blogs, we’ll be looking into each of these treatments and how research is making sure they are as effective as possible, with thoughts from leading experts in the field.
Part one in this series starts with chemotherapy. We spoke to Professor Rob Stein, a researcher based at University College London and a medical oncologist at the University College Hospital Cancer Centre, to hear his thoughts on the past, present, and future of this treatment.
Chemotherapy and breast cancer treatment
“In early breast cancer, the objective of any treatment is cure, to put it very simply. With chemotherapy, we aim to eradicate any breast cancer cells, wherever they may be in the body.
“In advanced disease however, things are different because the objective is to control the disease for as long as possible, whilst minimising the disruption to quality of life. This is an important consideration for people with secondary breast cancer – if you’re treating a patient but making a significant amount of their remaining life miserable, then perhaps you should think twice”.
Whilst it is clearly a useful treatment, Rob acknowledges that “chemotherapy has a bad reputation in the minds of the general public, without a shadow of a doubt”. There are some side-effects that a lot of breast cancer patients experience – tiredness, sickness, and hair loss being some of the most common – and others which are rarer but can be life-threatening.
Research over the years has helped doctors find ways to control symptoms – for example, the development of anti-sickness medicines to combat nausea has improved quality of life for many patients, and has enabled more people to tolerate and benefit from chemotherapy.
A bright idea from a dark history
What many people don’t know about chemotherapy is that these drugs came as a result of one the darkest periods of history – the Second World War.
After a group of American sailors was exposed to the chemical weapon mustard gas during an attack on an Allied base in Italy in 1943, scientists were intrigued to find that many of them had fewer white cells in their blood. They guessed that if chemicals in mustard gas could kill normal healthy white blood cells, they might also be able to kill cancerous blood cells too. Trials started soon after, and sure enough, drugs based on mustard gas were found to be an effective treatment for blood cancers like leukaemia and lymphoma – and so modern cancer chemotherapy began.
One of the drugs that were developed during this time was cyclophosphamide, which many breast cancer patients still receive today. Newer drugs have been developed – some from unusual sources, such as taxanes which were originally isolated from the bark of yew trees. But this use of old drugs for many decades alongside new ones is not so surprising to Prof Stein. “Whilst these old drugs have been refined, they still remain effective. Newer drugs have come along but they are not so much better that we should stop using the drugs from the early days of chemotherapy.”
Making better decisions
What is next for chemotherapy? For Prof Stein, the major area of focus for research into chemotherapy now is to ensure that patients only receive chemo if they need it.
For most people with primary triple negative or HER2-positive breast cancer, chemotherapy is considered to be an essential part of their treatment. However, the benefit is less clear-cut for people with hormone-positive breast cancer, so these patients are offered chemotherapy if there’s a high risk that their breast cancer might come back or spread in the future.
Currently, this risk is calculated using features such as the size and the grade of the tumour, and whether the cancer has already spread to lymph nodes near the breast. But Rob thinks this might not be a perfect measure:
“At the moment, we’re giving chemotherapy to lots of people who are probably unlikely to benefit. Up to now, we’ve used traditional risk factors to decide which patients should receive chemotherapy – but this is a bit of a ‘one size fits all’ approach.”
He thinks a better option may be to use ‘molecular tests’, which include Oncotype DX, EndoPredict, MammaPrint, and Prosigna amongst others. Instead of looking at the appearance of the cancer cells, these tests look at the activity of specific genes inside cancer cells, to give tumours a ‘score’ of how aggressively they are behaving.
“These tests could tell us two things. First is prognosis, that is the risk of recurrence – and the evidence that these tests can predict prognosis is extremely good. They also potentially have a second use, which is predicting how a tumour is likely to respond to chemotherapy – this could be particularly useful, and help us use chemotherapy in a much more rational way.”
For Rob, the priority now is for research to confirm that these tests actually work, and several clinical trials are ongoing to determine whether these tests can accurately identify patients who could safely avoid chemotherapy, including a trial called OPTIMA which Rob is leading. The findings of some of these trials are already starting to be released, and we’ll continue to see further results in the coming years.
Predictions for the future
One thing that is clear to Rob is that chemotherapy will still be a key component of treatment for decades to come – despite his earlier predictions…
“I was involved in the development of a targeted treatment in the 1990s which is currently in phase III clinical trials. Our expectation at the time was that these new drugs were going to make chemotherapy a matter of history – that was clearly wrong!”
Whilst chemotherapy is here to stay, the goal now is to pinpoint much more accurately who will benefit from it, and who will not, to ensure that everyone receives the treatment that’s right for them.
Keep an eye out for future posts on surgery and radiotherapy as part of our treatment blog series coming soon. In the meantime, you can read the latest research stories in our research blog.