In our previous blog we discussed how we hope to prevent as many people as possible getting breast cancer.
But for those whose breast cancer we can't prevent, the aim is to treat it effectively - and this is where early detection and diagnosis is critical, as Prof Stephen Duffy from the Centre of Cancer Prevention at Queen Mary University of London says:
“Early detection is one intervention which has a universal potential benefit. We can inhibit, prevent or treat hormone dependent cancer with drugs like tamoxifen and aromatase inhibitors, and treat HER2 positive disease with Herceptin, but earlier diagnosis can potentially benefit all cancers, regardless of biological profile.”
The earlier a woman's breast cancer is diagnosed – either by breast screening, or by going to her doctor with symptoms – the better her chance of survival. So what do we need to do to make sure that everyone has their cancer caught early?
In the UK about one third of all breast tumours – roughly 16,000 a year – are picked up through the breast screening programme, so it’s vital that we make sure that breast screening is fit for purpose.
At the moment the NHS breast screening programme invites women between the ages of 50 and 70 to have a mammogram every three years. Women at higher risk of breast cancer due to their family history are offered additional screening depending on their risk: for example, they might be invited to start screening at a younger age or more regularly, and maybe receive different screening techniques such as MRI.
Dr Susan Astley from the University of Manchester explains why we need to continue to improve this ‘personalised screening’ approach:
“Further research is necessary to establish the optimum strategy for personalised breast screening. We have a range of imaging techniques, but need to determine the most effective way of using them to detect cancers before they become more difficult to treat.”
We also need to make the most of new developments in technology. Like replacing a film camera with a digital camera, most mammography and other x-ray images are now fully digital. Whilst this has made it easier to take and share images within hospitals, another benefit for radiologists is that computers could be used to analyse the digital mammogram image automatically to help spot breast tumours, as Dr Astley explains:
“Digital mammography has paved the way for the development of novel imaging biomarkers, and for work to improve mammographic Computer Aided Detection (CAD) systems, in which potential abnormalities are identified automatically and prompts are generated to help expert readers interpret the mammograms.”
One area this computer analysis could be particularly helpful is in assessing breast density, which is the ratio between the mammary gland tissue compared to the fatty tissue in the breast. High breast density is a risk factor for breast cancer but it is currently difficult to measure consistently. Dr Astley is being funded by Breast Cancer Now to find ways to analyse images from a new type of ‘3D mammogram’ to measure breast density, and could help to provide more accurate information about a woman’s breast density and so her risk of breast cancer.
Researchers are working towards ensuring more women benefit from a screening programme that is adapted to their individual breast cancer risk. The first step to achieve this will be to find ways to accurately calculate a woman’s individual breast cancer risk. This will have to incorporate many risk factors risk that are not currently considered in the breast screening programme, such as lifestyle factors such as obesity and alcohol intake, and mammographic breast density.
One of the main risks of breast screening is a phenomena often called ‘over-diagnosis’, or ‘over-treatment’. This is when a woman is diagnosed with breast cancer that is detected on a mammogram that would not have otherwise been picked up because it would not have become harmful.
It has been estimated that every year, about 4,000 cases of breast cancer detected by screening are in fact over-diagnosed. However, it is currently not possible to tell whether a tumour is likely to become harmful or not – so all women are offered treatment regardless, meaning over-diagnosis leads to over-treatment.
It is important that we prevent people being treated for breast cancer needlessly, and to do this, we need to find ways to determine which screening-detected breast tumours are life-threatening and which could be left alone.
Breast Cancer Now-funded researchers Dr Mike Allen and Prof Louise Jones found that a molecule called αvβ6 could be used to predict which cases of DCIS are more likely to progress into invasive breast cancer, and we continue to fund research in this area.
In the meantime, screening by mammography is the best tool we have to diagnose breast cancer early and the benefits do outweigh the risk. But because there are risks, it’s important women make their own decision to attend or not. We have developed an award winning interactive guide to breast screening to explain the benefits and the risks, including over-treatment to help them decide.
Getting the message out
Whilst breast screening will remain an important tool for early diagnosis, two out of three breast tumours are diagnosed by spotting symptoms of the disease, so it’s critical that women know what to look for.
That’s why Breast Cancer Now has a simple message – Touch Look Check, or TLC – that encourages women to be breast aware. Being breast aware simply means knowing what your breasts look and feel like normally, being on the lookout for any unusual changes and getting them checked out by your doctor. The TLC message has already reached millions of people, and it is our ambition that by 2025 we can reach three-quarters of women in the UK to continue to improve awareness of the disease and its symptoms.
Our ambition for the future
Making women aware of the symptoms of breast cancer and ensuring that breast screening is as effective as possible are just some of the ways we hope to detect and diagnose breast cancer earlier. By 2025, we believe we will have found ways to diagnose an extra 2,850 women each year at an earlier stage, giving them a better chance of successful treatment.
Given the progress we’ve already made, we believe this is an achievable goal, and Prof Duffy agrees:
“So many of the major steps forward in screening and treatment of breast cancer occurred between the 1970’s and 2000’s. A heck of a lot can happen in thirty years, with the will and resources.”
Read the previous blogs in the series: