Advancements in Breast Cancer Screening: Can Research Enhance an Already Effective Program?
Every October marks Breast Cancer Awareness Month. Last week we looked at the landscape of breast cancer in Wales, breast cancer screening and what that involves, the signs and symptoms of breast cancer and some of the steps that can be taken to reduce the lifetime risk of developing the disease.
This week we discuss breast cancer screening in more depth and pose the question: can research improve an already effective screening programme?
Breast Cancer Screening
Before any screening programme can be rolled out nationally, the risks and the benefits of such screening in a population of people that don’t have any symptoms must always be considered and assessed carefully, with strong evidence provided to show that the advantages far outweigh the disadvantages.
Without question, breast cancer screening saves lives and understandably most women welcome the opportunity to participate when invited. However, as the below diagram demonstrates, there are downsides to the programme.
Current knowledge indicates that out of every 200 women invited for breast screening,15 will be found to have breast cancer. All 15 of those women will be treated and 3 will still eventually succumb to the disease.
In an equal number of women who are not screened, there will still be 15 cases of breast cancer – 8 women will be treated and survive and 4 will eventually succumb to the disease. Strikingly, 3 of the 15 cases of cancer will be tumours that would have never become evident or caused a problem during the person’s lifetime, yet they will have still undergone treatment.
In essence breast cancer screening leads to the overtreatment of 3 women to save 1 life.
However, there are caveats to the studies that gave rise to these calculations, as some are deemed to be limited in nature and therefore may not provide a full picture.
That being said, it doesn’t mean that there is no room for improvement in breast screening strategies to avoid overtreatment where possible, to provide more accurate screening tests for high-risk women of younger age and to help women make better and more informed future decisions with regard to possible options.
Cancer Research Wales is currently funding a team of scientists at Swansea University to develop an AI-based blood test which is showing promise at detecting early-stage breast cancer. Their studies are also investigating whether the blood test can detect high-risk pre-invasive tumours or the non-invasive condition ductal carcinoma in situ, or DCIS for short.
DCIS is a condition where cells that line the milk ducts within the breast have started to turn cancerous. However, at this stage the outgrowth of these cells is confined to milk duct with no evidence of spread into the main breast tissue, which is a more serious stage of development.
It is known that some cases of DCIS will progress to invasive breast cancer, with estimates varying from 20%-50% of all cases. Even then, it is notoriously difficult to discriminate between which cases of DCIS will need definitive early treatment and cases that can simply be safely monitored. Survival rates for DCIS are 98% at 10 years regardless of whether treatment is given or not. This raises an important question of whether current breast screening strategies can be further improved to prevent overtreatment in some women.
The BrCaSPECT project led by Professors Dean Harris and Peter Dunstan at Swansea University will analyse the bloods of over 300 patients with either breast cancer, DCIS or benign breast disease and will be compared with 160 control samples. Hospitals in Swansea Bay, Cwm Taf Morgannwg and Aneurin Bevan University Health Boards are about to start recruiting patients to the study.
The test is based on Raman spectral analysis which involves using lasers to ‘excite and activate’ blood samples, with the resultant energy that is released forming a signature pattern which is unique to the molecules present in the blood at that time.
It is hoped that an AI approach will detect certain ‘molecular fingerprints’ in the blood that can detect the more aggressive cases of higher risk DCIS which have the potential to become invasive more rapidly. Avoiding overtreatment in more indolent ‘low-risk’ cases where we have greater confidence that the cancer cells forming the DCIS will remain contained within the milk duct, would spare patients unnecessary surgery.
The unique molecular ‘fingerprints’ that are detected in the blood will represent various biological matter that has been secreted into the blood by the DCIS. This gives the added advantage that this information can be used to discover possible new therapeutic targets, leading to treatments that are less invasive and safer in those cases of DCIS that do need prompt treatment. Such an opportunity to create gentler treatments, or to use routine drugs already used for other conditions, could provide a better quality of life for women with DCIS regardless of its potential to progress.
Professor Dean Harris
“We are very excited to apply our colorectal cancer detection model to another common type of cancer. We have identified areas within the detection and treatment pathways for breast cancer that could be streamlined for more value-based patient care and earlier detection, using the blood test findings.”
Next week we will discuss male breast cancer and what improvements can be made to support this currently underserved patient group.
If you would like to find out more about Cancer Research Wales and the ways in which you can help support our research here in Wales, please visit our website here.