New Debate about the 'Worth' of Breast Cancer Screening

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For many years the UK has been proud to offer the most extensive breast screening programme in Europe and the programme has widely been thought to have been successful in preventing death from breast cancer.  However, in more recent years, the role that breast cancer screening has to play in reducing the number of deaths has come under closer scrutiny, particularly in light of the advances made in terms of treatment available.  This issue is now under the spotlight and has been widely commented upon in the media.

Where does this concern originate from?

In 2010, the Journal of Medical Screening published a paper compiled by eight eminent scientists who had looked at the data available from both a Swedish and an English study.  It looked at the impact of breast cancer screening over a 20 year period on women aged between 50 – 69 years.  The paper concluded that 'The benefit of mammographic screening in terms of lives saved is greater in absolute terms that the harm in terms of overdiagnosis.  Between 2 and 2.5 lives are saved for every overdiagnosed case.'

On this basis, the UK review of breast cancer screening carried out in 2010 recommended that screening provided more good than harm, and should continue.  However, there are other studies that have been carried out that dispute these figures, including a Nordic review by the Cochrane centre, which concluded that for 2,000 women invited for screening for 10 years, only one life will be saved but 10 cases will be overdiagnosed.

On 25 October 2011 the British Medical Journal (BMJ) published an open letter from Susan Bewley, professor of complex obstetrics at King's College London, sent to Professor Sir Mike Richards, national clinical director for cancer and end of life care, together with Professor Sir Richards' response.

Professor Bewley expressed her concerns that women were not being given sufficiently accurate information to allow them to make an informed decision about whether or not they a) wanted to be screened for breast cancer at all, and b) whether they would then opt for further investigation and/or treatment if the screening suggested that something were amiss.  Professor Bewley referred to the Cochrane review and expressed concern that the NHS breast screening position was expressed too optimistically in favour of screening, without sufficiently addressing the risk of overdiagnosis and the associated problems that this can bring.  She also surmised that in view of the improved standard and methods of treatment available for breast cancer sufferers today, as opposed to 20 years ago, the value of breast cancer screening has significantly diminished.

Professor Bewley herself had declined to take up the offer of breast cancer screening despite a strong familial history of the disease.

Professor Sir Richards in his reply acknowledges that there are differing views held by different groups of well respected scientists.  At present the advice of the independent Advisory Committee on Breast Cancer Screening (ACBCS) is that 'breast screening saves lives and that the benefits considerably outweigh the harms' and breast screening will continue for the time being to be routinely offered to women from age 50 to 70 years.  However he does confirm that accurate and understandable information is vital in ensuring that individuals are able to make an informed choice.  In light of the differing views as to the efficacy of breast cancer screening, Professor Sir Richards has requested that an independent review take place into the research evidence, with assistance from independent advisors.  He concludes that 'Should the independent review conclude that the balance of harms outweighs the benefits of breast screening, I will have no hesitation in referring the findings to the UK National Screenings Committee and then ministers.'

What are the 'risks' of breast cancer screening and what is 'overdiagnosis'?

In terms of the studies being considered above, the 'risks' of breast cancer are generally those of 'overdiagnosis' and psychological distress due to false positive results being given, or whilst waiting for the results from further investigations having had an abnormality detected at screening, which later transpires to be benign.

Overdiagnosis is referred to when cancer is diagnosed as a result of screening that would not have been diagnosed in the woman's lifetime.  This usually (although not always) means the cancer would have remained asymptomatic and that the individual would have died of some other cause.  The concern is that once a woman knows that the cancer is present, she must then face a number of other decisions and often treatments, which would not otherwise have to be considered or endured, and which ultimately will not prolong, and may even shorten her life.

Comment

I speak as a woman below the current screening age and as a clinical negligence lawyer, not as a clinician or as somebody that has been personally affected by this issue as yet.  However, surely the point is being missed; that breast cancer screening is an invitation only, it is not in any way mandatory. 

I agree that it is imperative to make available clear and accurate information to both treating clinicians and the public about the whole process of screening, the benefits, the possible adverse implications, and the choices that may have to be considered in the event of a suspicious screen.  Perhaps more needs to be done to ensure that this information is adequately communicated to all those eligible for screening.  However, is it not just a little insulting to infer that if this information were readily accessible, each individual would not be able to decide for herself whether or not she wished to participate in a screening programme?

All the studies under discussion agree that breast cancer screening between the ages of about 50 to 70 does save lives, although the number of lives saved per 1,000 women screened does differ quite significantly depending upon which study is being considered.  The implication from some quarters of the media is that the current debate has arisen out of concern that the risks of breast cancer screening may outweigh the benefits and that screening may therefore be scrapped.  However, the issue being discussed is the importance of ensuring that clear, accurate and up-to-date information is made available to the public and those responsible for determining public spending priorities, about the risks and benefits involved in breast cancer screening.  The purpose of the review is to re-evaluate the data available from various studies with the aim of forming a definitive view on the merits or otherwise of the screening programme in terms of lives saved versus overdiagnosis.

In terms of the merits of the screening programme generally, much depends upon what your interpretation of the words risk and benefit is.  The figures quoted from the studies generally refer to deaths prevented as a result of screening (the benefit) and number of cases of overdiagnosis (see above - the risk).  The BBC reported that approximately 2.7 million women are offered breast cancer screening each year and that this results in almost 17,000 cases being detected.  From a personal perspective, I consider both peace of mind from a clear screen, and earlier diagnosis of malignancy with greater choice of less aggressive treatment options, as distinct benefits attributable to breast cancer screening.  I understand that some may choose not to know and to continue with their lives in blissful ignorance, whether or not they have concurrent health problems, but the screening programme does not take away this choice.  Some may feel pressured or intimidated but again that is where the importance of accurate information comes in, giving people the confidence to make their own informed decision.

As a lawyer who has sadly acted for two individuals diagnosed with terminal breast cancer in their early forties over the past year, I am in favour of expanding the screening programme to include women of a younger age, should they wish to participate.  I am aware that this will have cost implications and that these are difficult times for those responsible for allocation of NHS budgets, but from my point of view as someone who has had the almost impossible task of having to quantify the 'value' of someone's life, a life saved and a family kept together, is worth the cost.

Final thoughts

A woman I have unfortunately not had the pleasure to meet attended her GP twice over a one year period complaining that she could feel a lump in her breast.  She was 44 years of age and a single parent.  She was in a low risk age group and there was no clearly defined lump felt by the GP.  The lady moved to New Zealand, a country that offers screening from the age of 45.  She was diagnosed with a large tumour in that breast, but sadly it was too late for the cancer to be successfully treated and she died within two months, leaving a 17-year-old daughter.  How can you put a price on her life? 

If you are worried about any change in your breast and want this to be investigated further, go to your GP and be insistent about a referral to a breast clinic.  This does not have to be part of a breast screening programme and GPs are obliged to make referrals in a number of circumstances (Please refer to the NICE guidelines attached).  A screening programme is just that – something that is made available to all that fulfil the programme criteria.  It is not intended to replace the investigations and tests that are available if an individual patient has particular concerns or symptoms.




Useful Links

1. Breast Screening: A Pocket Guide

2. National Institute for Health and Clinical Excellence: Referral guidelines for suspected cancer

3. Best practice diagnostic guidelinesfor patients presenting with breast symptoms

4. Breast Cancer UK

5. Breast Cancer Care



For further information, please contact Kym Provan, a Senior Solicitor in our Clinical Negligence Team, on 023 8085 7317 or at kym.provan@bllaw.co.uk