Clare Rogers Consultant Breast Surgeon Doncaster and Bassetlaw Hospitals

* Principles of Breast Screening * Brief overview of NHSBSP * Management of screen detected lesions * Benign * Indeterminate * Malignant * Controversies * False positives and negatives * Lead time bias * Overdiagnosis/ Overtreatment * The evidence

* Breast cancers are relatively slow growing and slow to metastasise * If caught early, treatment will be curative * Early treatment is more likely to involve breast conservation * Screening a selected age group at a rising risk of breast cancer but lower risk of mortality from other causes will save lives

* Catchment population is women age 50 – 70 * Age limits currently being extended to 47 – 73 * Test of choice is 2 view mammography with double reading 3 yearly * Recall by GP practice * Women at very high risk of breast cancer (family history, previous mantle RT) can be referred by a specialist at an earlier age

* Attends for MMG * Normal/Benign – letter of reassurance, recall in 3 years * Recall for further assessment * Further assessment could include * Compression views * Magnification views * USS * Needle core biopsy * Stereo * US

* MDT meeting * Benign – clinic for results and discharge * Inadequate biopsy – repeat * B3 or B4 – wire localised diagnostic excision biopsy (BSP standard <20g) or vacuum assisted large core excision (mammotome, encore etc.) * Malignant – surgeon and breast care nurse see to give diagnosis and offer treatment

* Manage the same as symptomatic cancer of same stage * US axilla +/- biopsy to assess axillary nodes * If normal, sentinel node biopsy * If malignant, needs axillary clearance * SLNB not needed for localised DCIS * Choice of surgery depends on size of abnormality, location, breast size, multi- focality, patient choice * Wire localisation for impalpable lesions for WLE

* MDT discussion * Treatment same as for symptomatic cancer of same stage

* Screening mammography * Will miss around 10% cancers, depending on patient age and breast density * Uses ionising radiation * Learning curve for reporters * Numbers needed to maintain skills * Core biopsy needed to confirm diagnosis of any defined lesion * Painful * Risk of haemorrhage and infection * Psychological stress of recall and waiting for test results

* The patient gains false reassurance from a normal mammogram * She may delay presenting when she develops symptoms

* The patient has cancer surgery for a lesion that is benign * Very rare * Usually detected by pathologist looking at excision specimen

* The screening test detects the disease earlier but does not change the course * The patient lives with the knowledge of cancer and effects of treatment for longer, with no benefit to her overall survival * e.g. a small grade 1 cancer which would not have metastasised if left until palpable * A tumour which is already metastatic at presentation * Lead time bias increases the prevalence of the disease but does not change the absolute mortality

* Breast Screening uptake in the UK is 73% * Women attending screening are more health aware * The same women are likely to present earlier with a symptomatic cancer, and with other health problems * This leaves a group of patients who are not screened and present late, skewing the apparent benefits in favour of screening * This may explain why 5 year mortality for women with screen detected DCIS is lower than the population all cause 5 year mortality

* Detection of a lesion which would not have become clinically relevant in a patient’s lifetime * e.g. low grade DCIS and grade 1 cancers * Patients with other serious co-morbidities whose lifespan is shortened * Physical side effects * Psychological * Financial * Over-diagnosis increases the incidence and prevalence of the disease without changing the number dying from the disease * Better treatments for patients at risk of dying of breast cancer will reduce the death rate

* The Swedish two county trial of mammographic screening for breast cancer: recent results and calculation of benefit * Tabar et al. Journal of Epidemiology and Community Health 1989;43: * The Swedish Two-county Trial Twenty Years Later : Updated Mortality Results and New Insights from Long-Term Follow-up * Tabar et al Radiologic Clinics of North America 2000;38(4):

* Breast cancer (female) – Screening, NHS Choices, 2012 * 1400 lives are saved each year by the UK BSP. For every 400 women screened for 10 years, 1 life is saved = 5 lives per 2000 women. 5 women are over-treated per 2000 screened * Screening for Breast Cancer with Mammography, Nordic Cochrane Centre 2012 * For every 2000 women screened for 10 years, 1 life will be saved and 10 women will be over-treated. 200 women will receive a ‘false alarm’ i.e. recall +/- biopsy with a benign outcome * The Benefits and Harms of Breast Screening – an Independent Review. Marmot MG and the Independent UK Panel on Breast Screening. Lancet 2012;380(9985): * For women screened over 20 years, 43 deaths prevented and 129 over-diagnosed * Breast Screening * Overdiagnosis: When Good Intentions Meet Vested Interests. Iona Heath BMJ 2013;347:f6361

* The introduction of the Breast Screening programme in the UK led to the first cancer MDT meetings * These are now recognised as best practice for all cancer types * Variation is reduced and standards of care raised through MDT working * Is this the reason that Breast Cancer Mortality is falling? * If breast screening were found not to be beneficial, could it be stopped?

* UK BSP women aged 50 – 70 * Extended for high risk women * There are benefits and harms about which the experts disagree * Screen detected cancers are treated the same as symptomatic cancers of the same stage