Enhanced breast cancer screening could detect an extra 3,500 cancers per year in UK, Cambridge-led trial shows
Extra scans could detect an extra 3,500 breast cancers and save up to 700 lives per year in the UK, say University of Cambridge researchers.
A large-scale trial found additional scans for women with very dense breast tissue could pick up cancers that are difficult to spot on standard mammograms.
About 10 per cent of women have very dense breasts, which means they have more fibrous and glandular tissue and less fatty tissue than other women. Between the ages of 50 and 70 they are four times more likely to develop breast cancer compared to those with low breast density.
Mammograms - the breast X-rays used for breast screening - are less effective at detecting cancer among these women because denser breasts look white on mammograms, making it harder to spot small, early-stage cancers, which also appear white.
A trial of more than 9,000 women across the UK with dense breasts and a negative result for cancer from mammograms found 85 cancers using additional screening methods.
Per 1,000 women screened, two of the methods detected 17 to 19 cancers not seen in mammograms.
Adding either of the methods - known as CEM (contrast enhanced mammography) and AB-MRI (abbreviated magnetic resonance imaging) - to existing breast screening would detect an extra 3,500 more cancers a year in the UK, the researchers say.
Given that screening is believed to reduce mortality for about 20 per cent of cancers detected, it could mean an extra 700 lives are saved annually, although more work is needed to confirm this assumption as cancers detected through screening are not always life-threatening.
The BRAID trial also included another scanning method called ABUS (automated whole breast ultrasound), that detected cancers not seen in mammograms, but it proved three times less effective than CEM and AB-MRI, which detected cancers half the size.
About 2,000 women were scanned with each method. CEM detected 19 cancers per 1,000 women, AB-MRI found 17 per 1,000 and ABUS found four.
Mammograms detect about eight cancers per 1,000 women with dense breasts.
The Cambridge-led trial, which recruited across 10 UK sites and included over 2,000 women at Addenbrooke’s Hospital, is the first to compare additional imaging methods and demonstrate their value in early detection as part of widespread screening.
Professor Fiona Gilbert, from the Department of Radiology at the University of Cambridge and honorary consultant radiologist at Addenbrooke’s, who led the trial, said: “Getting a cancer diagnosis early makes a huge difference for patients in terms of their treatment and outlook. We need to change our national screening programme so we can make sure more cancers are diagnosed early, giving many more women a much better chance of survival.”
More than 2.2 million women receive breast screening each year in the UK.
Trial statistician and screening programme expert Prof Stephen Duffy, emeritus professor at Queen Mary University, London, said: “The NHS Breast Screening Programme has made a huge difference to many lives. Thanks to these results we can see that the technology exists to make screening even better, particularly for the 10 per cent of women with dense breast tissue."
Dr David Crosby, head of prevention and early detection at Cancer Research UK, said: “Breast cancer screening is for people without symptoms and helps to spot the disease at an early stage, when treatment is more likely to be successful. But having dense breasts can make it harder to detect cancer.
“This study shows that making blood vessels more visible during mammograms could make it much easier for doctors to spot signs of cancer in women with dense breasts. More research is needed to fully understand the effectiveness of these techniques, but these results are encouraging.
“Remember, having dense breasts is not something you can check for yourself or change, but if you’re concerned at all, you can speak to your GP.”
At the moment, the UK National Screening Committee does not recommend any additional imaging for women with dense breasts who have a negative result on a mammogram.
A Department for Health and Social Care spokesperson said: “Research is being conducted into the use of additional tests for women with dense breasts, as part of the NHS breast screening programme.
“The UK National Screening Committee is reviewing this evidence as it becomes available.”
The research was published last Thursday (22 May) in The Lancet and was funded by Cancer Research UK with support from the National Institute for Health and Care Research (NIHR) Cambridge Biomedical Research Centre (BRC).
Louise: ‘It was a huge shock’
Among those invited to participate on the trial was grandmother of four Louise Duffield, 60, from Ely, who was diagnosed with early-stage breast cancer as a result.
Louise, who works in local government, participated following her regular mammogram screening, which showed that she had very dense breasts.
Louise had an AB-MRI scan, which identified a small lump deep inside one of her breasts.
“When they rang to say they’d found something, it was a big shock. You start thinking all sorts of things but, in the end, I just thought, at least if they’ve found something, they’ve found it early. The staff were brilliant, and so supportive,” she said.
A biopsy soon confirmed she had stage 0 (very early) breast cancer within the ducts of one of her breasts and six weeks later Louise underwent surgery to remove the tumour, by which time it had already grown larger than it appeared on the scans.
“It’s been a stressful time and it’s a huge relief to have it gone. The team have been fantastic throughout. The tumour was deep in the breast so, if I hadn’t been on the trial, it could have gone unnoticed for years,” she said.
“I feel very lucky, it almost doesn’t feel like I’ve really had cancer. Without this research I could have had a very different experience.”
The tumour’s location meant it would have been difficult to find through self-examination and it would have been at least three years before she had been invited for another routine mammogram.
Louise had a short course of radiotherapy and is now cancer free. She will continue to be monitored for several years and will attend her regular mammograms every three years as part of the national breast cancer screening programme.
“This experience has highlighted to me how important screening is. If I hadn’t had the mammogram, I wouldn’t have been invited to the trial. Getting treated was so quick because they found the cancer early,” she said.