Key Research in Breast Screening
Key Research in Breast Screening |
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The NHS Breast Screening Programme is evidence-based. Where aspects of it needed further investigation, research trials were set up. Details of the key research used to inform the programme are below.
Age Extension Pilot StudyIn December 2007, the Department of Health's Cancer Reform Strategy announced that from 2012 the NHS Breast Screening Programme would be extended to cover women between the ages of 47 and 73. This means that all women will get two extra screening invitations in their lifetime. It also means that all women will get their first screening invitation before their 50th birthday. The age extension will be phased in across England over a three-year period, with full coverage from 2012. Before that begins, however, a pilot study is being undertaken in six areas across England that have volunteered to take part. The pilot study will provide information which can be used in the planning and rollout of the age extension across the rest of England. Women aged 50-70 in the pilot areas are invited for screening as usual. In order for the pilot to be evaluated, the female population that falls within the extended screening ages has been randomised. Around half of the women aged 47-49 and 71-73 in the pilot areas have been selected at random to receive screening invitations. This means that the pilot only affects some women aged 47-49 and 71-73, as all women aged 50-70 continue to get their screening invitations as normal. The results of the pilot will be available by the end of 2009. For more information see http://clinicaltrials.gov/ct2/show/NCT00890864?term=NCT00890864&rank;=1. How often women should be screened: Frequency trialThe Frequency Trial concluded that the NHS Breast Screening Programme has got the interval between screening and invitations about right at three years, compared with more frequent screening. The trial was organised through the United Kingdom Coordinating Committee on Cancer Research (UKCCCR) and was supported by the Medical research Council, Cancer Research UK and the Department of Health.1 UKCCCR Randomised Trial, European Journal of Cancer, 2002 - PDF format 186Kb Age at which women are screenedThe World Health Organisation's International Agency for Research on Cancer (IARC) concluded that there is sufficient evidence for the efficacy of breast screening of women between 50 and 69 years. For women aged 40 - 49 years, the group concluded there is only limited evidence for a reduction. Age trialThis study considers what benefit, if any, is gained by inviting women for screening from age 40. Around 53,000 women aged 40 and 41 are being invited for annual screening for eight or nine years; a control group of around 106,000 women, who are not invited for screening but receive usual NHS care, are being monitored for breast cancer over this period. After they reach age 50 both groups are automatically eligible to be invited every three years as part of the NHS Breast Screening Programme.The trial started in 1991 and randomisation ended in 1996.It is funded by the United Kingdom Coordinating Committee on Cancer Research (UKCCCR). It will run for 15 years and is being coordinated by the Cancer Screening Evaluation Unit (CSEU) of the Institute of Cancer Research. The primary outcome measure will be a comparison of mortality from breast cancer in the two trial arms. Interim results are currently only available to subscribers to the on-line British Journal of Cancer. Here are the links to abstracts.
DCIS: The Sloane ProjectOne in five breast cancers detected by screening is non-invasive. The term "non-invasive" means that the cancer has not developed the ability to spread either within the breast tissue or to the rest of the body. The main type of non-invasive breast cancer, Ductal Carcinoma In Situ (DCIS), is found when still within the milk duct. It is not certain whether all of these will ever spread to the surrounding breast tissue and therefore, there is uncertainty about the treatment required. The NHS Breast Screening Programme is funding The Sloane Project, to improve the quality of care for women with screen-detected DCIS and other non-invasive breast cancers and atypical hyperplasias. It is a prospective audit, which aims to obtain good quality data from all UK breast screening units, and so produce the largest database in the world. By adding to our knowledge of the diagnosis, treatment and clinical outcomes of these diseases, the Sloane Project will provide an evidence base to inform the management of women with DCIS. Data collection for the project took place from April 2003 to March 2008. Small invasives trialThis trial is investigating the different methods of treating small invasive cancers, that is, those smaller than two centimetres in diameter. It is coordinated by the British Association of Surgical Oncology and is known as the BASO II Trial. It has now finished recruiting women and is following them up. Magnetic Resonance Imaging for Breast Screening ( MARIBS)The identification of two of the genes (BRCA1 and BRCA2) involved in inherited breast cancer has caused great public interest. A multi-centre trial, Magnetic Resonance Imaging for Breast Screening (MARIBS) compared regular mammographic screening and regular Magnetic Resonance Imaging (MRI) for women with a high risk of carrying one of these genes. It ran for five years and was coordinated by the Institute of Cancer Research and funded by the Medical Research Council and NHS Research and Development. Million women studyThis study is looking at the links between hormone replacement therapy (HRT). breast cancer and other diseases. The study, which is one of the world's largest ever cohort studies, has recruited one million women from amongst those invited for breast screening. The study is investigating how HRT affects a woman's breasts and other aspects of her health. Other factors being investigated include diet, childbirth, breastfeeding, vitamin and mineral supplement use, contraceptive and family history of illness. The study is being coordinated by Cancer Research UK. Over 65s pilotThe over 65s pilot project investigated how many women aged 65 to 69 would accept an invitation to screening. This followed a call by the Health Select Committee, in 1995, for the screening age to be increased to include women up to the age of 69 in the call and recall system. The pilots were set up in Leeds, Wakefield, Brighton and Nottingham and demonstrated that women in this older age group can be screened effectively and will accept screening invitations. Subsequently, the NHS Cancer Plan announced that the NHS Breast Screening Programme would be extended to women aged 65 to 70 by 2004. New ways of working in the NHS Breast Screening ProgrammeIn February 2002 all major stakeholders involved in the development, monitoring and evaluation of the New Ways of Working Project agreed that the four tier model of service delivery based on occupational standard was safe, robust and effective. The four tiers are:
Prevention trial (IBIS)The International Breast Cancer Intervention Study (IBIS) is designed to evaluate the effect of taking daily tamoxifen on the incidence of breast cancer in women with an increased risk. Recruitment to the IBIS I trial closed in 2000. The IBIS II trial which is still recruiting, is divided into two parts. The prevention arm is looking at the use of Anastrozole and the DCIS arm is looking at Anastrozole versus Tamoxifen. Details of IBIS I and IBIS II can be found at www.ibis-trials.org. Effect of deodorants on mammographic filmsDownload Report (Word Document 4243Kb). Screening centres advise women not to wear deodorants when attending for screening or assessment mammography. This is because it has been found that these can sometimes appear as artefacts (specks) on mammographic films. There is therefore concern that these artefacts may affect the film readers' judgement adversely. However the NHSBSP National Co-ordinating Group for Radiographic QA expressed concern that this policy was making radiographers' working environment unpleasant and questioned whether such guidance was really necessary. The National Co-ordinating Centre for Mammography was asked to investigate the following aspects.
Here are the conclusions and recommendations of the investigation: It has been shown that deodorants and anti-perspirants do have sufficient contrast to be visible on mammograms and can potentially be a source of artefacts. Aluminium compounds appear to be the main cause of this although even solid deodorants with no aluminium showed low levels of contrast which may be visible on films. Only the one liquid deodorant with no aluminium could be ruled out as a possible source of artefacts. Modes of advice given to the women attending for mammography depend partly on whether radiologists and other film readers can properly differentiate between artefacts caused by deodorants and clinically relevant features. Options for the advice include:-
The decision concerning which of these modes of advice to offer will be left to individual breast screening units. A hard copy of the full research report is available from the National Office on request. An Intervention to Increase Breast Screening UptakeResearchers at the University of Kent in Canterbury have undertaken a study to test whether a cost-effective intervention to increase uptake in the NHSBSP could be set up. Using a simple procedure based on the concept of implementation interventions the researchers asked women to make specific plans for attending for breast screening. They found that by encouraging women to plan for their first round of screening high attendance in subsequent rounds was likely to follow. For the full report see; An Intervention to Increase Breast Screening Uptake (PDF 123Kb). [1] The frequency of breast cancer screening: results from the UKCCCR Randomised Trial, European Journal of Cancer, 2002; 1458 - 1464 Computer-aided diagnosis in breast screeningIt has been suggested that computer aided detection (CAD), a system of bringing a mammography reader's attention to suspicious features, can help save time, manpower, and might help detect abnormalities that might otherwise be missed. An initial study (CADET I) carried out in 2004, used CAD to re-read 10,000 mammograms which had previously been read by two radiologists. This study showed that the accuracy of the single reader using CAD was the same as double reading of mammograms. CADET II is a follow up study aimed at testing CAD in the day to day environment of the breast screening programme. The three screening centres involved in the study have recruited 30,000 participants. Results are expected in 2008. Family History Study (FH01)A research project evaluating the effectiveness of mammographic surveillance for women under 50 with a family history of breast cancer is taking place. A cohort of 10,000 women under the age of 50 with a significant family history of breast cancer will be given regular mammographic surveillance over five years. Comparison of surgical and pathological data with completed and on-going population screening trials will be performed to obtain an accurate estimate of breast cancer mortality reduction. The change in health service resource use attributable to mammography will be compared with no screening and its cost effectiveness determined. The comparison with no screening will be presented in terms of the additional cost per cancer detected, per life saved and per life year saved. Details of the study and eligibility criteria can be found on the Family History Screening study website. An initial assessment of the merits of extending routine breast cancer screening to women aged 47-49 years to assist the appraisal of options for extending the NHSBSP, with appendix considering women aged 71-73The 2007 NHS Cancer Reform Strategy proposes extending the NHS Breast Screening Programme to women aged 47 to 49 and women aged 71 to 73. There are significant differences between each cohort in terms of incidence, compliance, treatment options, relapse rates, competing risks, screening test performance, and psychological impact of true and false positives. This study looks at targeting the younger cohort and compares it with the status quo. An extension of the modelling to the older cohort is included in the appendix. ScHARR Initital Assessment Report - June 2008 (PDF 183Kb) Tomosynthesis trialKing's College Hospital is conducting a trial into the use of new three dimensional digital x-ray technology, called tomosynthesis,for breast cancer screening and diagnosis. At present, two-dimensional mammography is the standard type of breast x-ray used in hospitals across the UK. Although recognised as safe and reliable in detecting the early signs of cancer, 2D mammography can be difficult to read because of tissue overlap. The so-called 'anatomical noise' associated with 2D imaging can sometimes hide cancers, or produce shadows which can falsely create the suspicion of cancer. The new technology enables doctors to look at separate 'slices' of the breast. The trial is designed to demonstrate whether this will be even more accurate than standard two-dimensional mammography. The 'digital breast tomosynthesis' technology works in a similar way to a CT (or CAT) scan, taking multiple images of the breast at different angles. The tomosynthesis slices are then viewed one at a time or put together into a cine loop for doctors to analyse. Tomosynthesis is simpler to implement than a CT scan and requires only small modifications to existing mammography systems, whereas CT requires large complex scanners. Over 150 women have participated in trial to date. DMISTDMIST also called A Screening and Diagnostic Trial to Compare the Effectiveness of Two Types of Mammography in Detecting Breast Cancer in Women was carried out in the USA. Among the objectives of the study were
A total of 49,500 participants (24,750 per arm) were studied and results were published in 2006-2008. |
 Breast screening programme index What happens at a What are the risks of breast screening? Frequently Asked Questions (FAQs) DCIS (Ductal Carcinoma Diethylstilbestrol (DES) exposed women Research | ||||||||
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