This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Women at increased risk of breast cancer who were offered enhanced screening were more likely to survive long-term. A study was carried out at a specialist clinic for women with a strong family history of the disease. It found that, 10 or 20 years after diagnosis, they were more likely to be alive than other women in England with breast cancer.
Enhanced screening means that women have their breasts checked (screened) from a younger age, and more frequently, than in the national screening programme.
The study was carried out over 30 years at a pioneering family history clinic in Manchester. Women’s risk of breast cancer is assessed at the clinic according to their family history (whether close relatives have had breast cancer), and genetic tests.
Other clinics in the UK and elsewhere have since introduced enhanced screening for women at increased risk. Guidelines from the National Institute for Health and Care Excellence (NICE) now support enhanced breast screening for women with increased risk. Since 2004, a series of guidelines have been issued in response to developments in risk assessment, genetic testing, screening, preventive drugs and surgery to reduce risk.
This study was carried out among women at moderate and high risk of breast cancer who attended the Manchester clinic. It explores the impact of enhanced screening on their chances of survival long-term.
What’s the issue?
Around 55,000 women are diagnosed with breast cancer in the UK each year. It is the leading cause of death in women aged 30-60.
Women have a higher risk of developing breast cancer if close relatives have had the disease. Some of these women may carry a gene fault, such as in BRCA1 or BRCA2, which increases their risk.
Since the 1980s, women with a strong family history of breast cancer have had enhanced screening and are offered more tests for more years than other women. NICE guidelines recommend that women with a moderate (17-29%) or high (30%+) risk of developing breast cancer are screened every year from the age of 35. They are examined by a doctor and have an X-ray of the breasts (mammogram). Screening begins at the age of 35 (or at 5 years younger than their youngest affected relative; earliest age for starting mammography is 30).
Women at moderate risk stop receiving annual screening aged 50. Women at high risk continue to receive screening every 12-18 months until they are 60.
This is the first large study to look at the long-term impact of enhanced screening in women at increased risk of breast cancer.
What’s new?
The study included 14,311 women who attended a Manchester clinic between 1987 and 2020. The clinic assessed family history and offered screening and prevention. The women all had a high or moderate risk of developing breast cancer.
Women were all offered the enhanced screening recommended by NICE (annual mammograms and clinical breast examinations). But more tests were introduced during the study period. Genetic testing for BRCA genes was offered more widely, and women carrying one of these gene faults were offered annual MRI scans from 2006 onwards. Some were included in other trials and had regular MRI scans as early as 1997. Some opted for surgery to remove both breasts (double mastectomy) and reduce their risk.
Over the course of the study, 649 women (5%) developed breast cancer. Most (62%) were detected by enhanced screening; and more than 2 in 3 cancers (69%) were early stage (grades 0-1).
The study found that, among women who received enhanced screening:
- most (91%) of those who were diagnosed with breast cancer were still alive a decade later; this is higher than the overall rate for 10 year survival from breast cancer in England (76%)
- those aged 40 and under (who would not be screened in the national programme) had especially high survival (94%) at 10 years
- 20 years after diagnosis, 92% of those carrying a BRCA1 fault were alive (similar to the overall rate); rates were slightly lower (85%) in women carrying BRCA2
- those who found a breast lump between screens (interval cancers) had lower survival (80% at 10 years)
- some types of breast cancer were related to less chance of survival: lobular cancer (in the milk glands), and cancers with certain molecular features (triple negative, or high-grade cancers ER+, HER2+).
Why is this important?
The researchers believe this is the largest study to date on a local approach to breast cancer risk and screening. The findings support existing NICE guidelines, which recommend annual MRI scans for women carrying faults in either BRCA gene.
However, the authors call for policymakers to reassess the guidelines for women aged 30-40 at moderate or high risk of breast cancer. NICE recommends screening from age 30+ only for women in the very high-risk category. A previous study by the same team showed that mammograms can effectively pick up breast cancer in women aged 35-39. Together, these studies suggest that annual mammograms before age 40 could improve survival in women at moderate or high risk.
This research may inform discussions with women considering whether to have a double mastectomy to reduce their risk of breast cancer. While surgery prevents almost all breast cancers, the findings show that MRI scans also effectively improve survival.
This study highlights the importance of family history clinics for women with a heightened risk of breast cancer. Further work by this research team has demonstrated gaps in the provision of these clinics in the UK. Without family history clinics, many women at increased risk will not receive enhanced early screening.
What’s next?
Women with lobular breast cancer had the lowest survival rates. The researchers suggest that further research is needed to find alternative screening methods. Shortened MRI scans, automated ultrasound and mammography using contrast dye could improve the sensitivity of scans while remaining cost-effective.
The study found early (grade 1) cancers in women who do not carry either BRCA gene. This suggests that other, undiscovered genes play an important role in the development of these lower grade breast cancers.
This research was carried out in a single centre, the Manchester family history clinic. It demonstrates the value of enhanced breast screening at an experienced centre. The researchers aim to publish an update on the women’s survival in 5 to 10 years’ time. However, further work is needed to establish whether the same results can be achieved in other settings.
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This summary is based on: Evans, DG and others. Breast cancer incidence and early diagnosis in a family history risk and prevention clinic: 33-year experience in 14,311 women. Breast Cancer Research and Treatment 2021:189:677–687.
The same research team looked at clinics which assess family history: Howell, A and others. Long-Term Evaluation of Women Referred to a Breast Cancer Family History Clinic (Manchester UK 1987-2020). Cancers 2020:12:12:3697
A study explored screening in younger women aged 35-39: Evans, DG and others. Final Results of the Prospective FH02 Mammographic Surveillance Study of Women at Increased Familial Risk of Breast Cancer. EClinicalMedicine 2019:7:39-46.
Information from the charity Prevent Breast Cancer.
Funding: This research was supported by the NIHR Biomedical Research Centre in Manchester.
Conflicts of Interest: The study authors declare no conflicts of interest.
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