Risk Assessment: Breast Cancer, Prediction and Screening

Progress Educational Trust
Darwin Lecture Theatre, Darwin Building, University College London, Malet Place, London WC1E 6BT
8 May 2014 6.30pm-8.30pm
This public event was organised by the Progress Educational Trust (PET) at University College London, and was supported by the Wellcome Trust. The event formed part of the PET project 'Breast Cancer: Chances' (which launched with the preceding event 'Relative Risk: Breast Cancer and Genetics', and continued with the events 'Risk Management: Breast Cancer, Business and Patents' and 'Breast Cancer Risk: Facts, Fictions and the Future').
A podcast produced by James Brooks, in which he interviews members of the speaker panel, can be listened to using the player below or alternatively can be downloaded by clicking here (.mp3 16.9MB).
James Heather has written a summary of this event for PET's flagship publication BioNews. The event is also discussed by Dr Ann Robinson (who chaired the speaker panel) in her BioNews article 'Breast cancer: breaking the chain', while patient and advocate Anna Wallace discusses the event here.
Understanding and measuring risk in medicine can be difficult, and this is certainly true of breast cancer. There are different types of risk - including absolute and relative risk, population and individual risk, lifetime risk and risk over a specific time period, and the chance and burden components of risk - that are easily confused in discussion of breast cancer, and that laypeople (and even experts) can find difficult to disentangle. There are also competing measures when it comes to assessing the prevention and treatment of breast cancer, such as efficacy (improvement in survival) and tolerability.
It is said that breast cancer screening involves a risk of overdiagnosis or misdiagnosis, but more fundamentally, there are subtle ways in which early detection due to screening might change our understanding of what breast cancer actually is. One challenge is the difficulty of predicting of predicting whether small invasive or in situ screen-detected tumours are liable to grow into a cancer that will result in symptoms during a patient's lifetime, whether they will grow too slowly for this to be the case, or whether they will shrink. This difficulty in predicting the fate of tumours means that traditional distinctions between 'pre-cancer' or 'pseudo-cancer' on the one hand, and cancer proper on the other hand, are blurred when screening for breast cancer. Furthermore, lead time bias can make it difficult to assess the pros and cons of screening.
Risk also plays an important part in the reproductive decisions of people who know they have a genetic predisposition to breast cancer, and who wish to avoid passing this predisposition on to their children. Preimplantation genetic diagnosis for BRCA1 and BRCA2 mutations is licensed by the Human Fertilisation and Embryology Authority,, and has been used in the UK to ensure that children are born without these mutations. But despite most types of inherited cancer predisposition showing autosomal dominant inheritance (meaning that on average half of a person's children will inherit the predisposition), counselling on reproduction is rarely included in guidelines on clinical management of breast cancer.
This event saw these and other aspects of breast cancer discussed in relation to genetics and risk, from contrasting perspectives, by a panel of experts.

Wendy Watson
Founder and Director of the National Hereditary Breast Cancer Helpline, and author of I'm Still Standing: My Fight Against Hereditary Breast Cancer
Paul Serhal
Founder and Medical Director of the Centre for Reproductive and Genetic Health, responsible for the UK's first baby born following preimplantation genetic diagnosis for BRCA1 mutations
Stephen Duffy
Professor of Cancer Screening at Queen Mary University of London's Centre for Cancer Prevention, and Director of the Policy Research Unit in Cancer Awareness, Screening and Early Diagnosis
Klim McPherson
Professor of Public Health Epidemiology at the University of Oxford's Nuffield Department of Obstetrics and Gynaecology, and former Chair of the British Breast Group

Dr Ann Robinson
GP and health commentator for the Guardian and BBC Radio 4

  Partners and supporters:
  Wellcome Trust