With better technology and training, coupled with an increase in the eligible population, more breast cancers are being detected in Ireland, and in other international screening programmes. With progress comes added complexity. A new study notes the rise in recall rates seen in BreastCheck - Ireland’s national breast screening programme. Our programme continues to evolve and learn to ensure we achieve the right balance between early cancer detection and the downsides of unnecessary investigations in women recalled, most of whom will not have cancer.
An evaluation of over two million mammograms from BreastCheck over a 20-year period (2000 to 2019) has found that the recall rates of women coming for screening have risen over this time. The recall rate is the proportion of women asked to come back for further tests after an initial or subsequent screening.
In this study the rise in recall rates for first-time attendees was higher than the rise in subsequent attendees.
- For first-time attendees, the recall rate has reached 10%, up from a 5.5% recall rate recorded earlier in the programme’s history.
- For women attending for subsequent screenings, the recall rate has risen from 2.3% to 3%.
Similar increases have also been seen in other international screening programmes across Europe, the UK and Australia.
Recall rates are typically higher in first-time attendees because there is usually no previous mammogram to compare to, which can provide reassurance without the need for more tests. The majority of these recalls are of no further concern, with results showing no evidence of cancer.
Our recall rate has risen over time, particularly for findings like asymmetries or calcifications that are sometimes benign. This reflects a wider pattern seen across many countries, where changing technology, patient demographics and lifestyle changes, and even the medico-legal environment all play a role.
The study has demonstrated that the main associated benefit of this increased recall rate is a rise in cancer detection rates, which it said was most likely due to significant improvements in imaging technology, specialist training, and the expertise of our screening teams. Every mammogram is reviewed by two consultant radiologists who have completed specialist breast imaging fellowships and read on average 20,000 mammograms a year - well above the international threshold shown to enhance accuracy.
In breast screening, the cancer detection rate is the number of breast cancers detected per 1,000 women screened.
The study found that in BreastCheck:
- the cancer detection rate increased from 6 per 1,000 to 7 per 1,000 women screened from 2004 to 2019
- the largest increase was seen in first time attendees – from 7 per 1,000 to 10 per 1,000 women screened
- cancer detection rates for women attending for subsequent screening increased from 5 per 1,000 to 6 per 1,000 women screened.
While some increase in recall rates is expected, especially with more sensitive imaging, it raises important questions about how to balance early detection with the downsides of unnecessary investigations in those women recalled. We know that women recalled for further tests can experience heightened anxiety and may undergo unnecessary investigations for benign breast changes or forms of breast cancer that may not progress to cause significant harm. The increased recall rate also imposes additional demands on cancer screening resources.
The study highlights the ongoing need for screening programmes across the globe to work together to understand the reasons behind increasing recalls. We need to define and agree what an optimal recall rate looks like. The authors suggest that the integration of artificial intelligence into breast cancer screening holds promise for enhancing diagnostic accuracy and reducing unnecessary recalls.
We continue to evaluate our performance and benchmark ourselves against best international practice, to ensure screening continues to offer more benefit than harm. In March of this year, our BreastCheck programme was re-accredited by EUREF (European Reference Organisation for Quality Assured Breast Screening). This award is an independent recognition of our high standards and quality of care.
Our aim is to continue to offer a high-quality screening programme that empowers women with accurate information and supports them to make informed choices. This research is part of this ongoing work.
- This study is published in the European Journal of Radiology: Evaluation of recall rates in the Irish national breast screening programme: Insights from two million screening mammograms