Reality not hype: the new genetics in primary care 

Session III: workshops

2. Cancer genetics

Facilitators:

Jon Emery (Centre for Medical Genetics and Policy, University of Cambridge)

Shirley Hodgson (St George’s Hospital Medical School, London)

Presentation

Professor Hodgson gave a short presentation on the prevalence, clinical features and management strategies of common inherited cancer syndromes. Dr Emery outlined the problems of dealing with cancer, a relatively rare disease with very common symptoms, in primary care. He then presented a computer programme aimed at assisting the referral process through compiling family history information and assessing an individual’s cancer risk (GRAIDS).

Discussion

In the ensuing question and answer session the following issues were raised:

There is an important difference between inherited and acquired genetic mutations: inherited (germline) mutations affect all your body cells and can increase your cancer risk, which often means that people develop cancer earlier than the average patient. Acquired (somatic) genetic mutations happen when otherwise normal cells go ‘wrong’, possibly due to environmental factors, and develop genetic mutations that then only affect the tumour, not the other body cells.

Questions were raised regarding the use of the computer programme in clinical practice: who would use the software, how would the professional relate to the patient, how long would a consultation take? Dr Emery explained that the model being piloted at the University of Cambridge is one where one member of a GP surgery becomes an ‘expert’. Patients would be referred to this expert for a 20 minute consultation.

Questions were also raised about unusual clusters of cancer, or clusters consisting not solely of bowel, breast and ovarian cancer. The facilitators agreed that if in doubt, primary care practitioners should contact their regional genetics centre for further advice. Contact details for all regional genetics centres can be found on the website of the Clinical and Molecular Genetics Society http://www.cmgs.org/

One participant expressed concerns about holding all this family information on record in their own surgery, as they would then be required to pass it on to insurance companies (see the summary of Dr Laurie’s presentation).

The speakers agreed with one of the participants that there was little ‘hard and fast’ evidence underlying the risk categorisations (average, medium, high) in cancer, but that they reflect management strategies, and basically express who qualifies for different screening options. However, apart from screening for high risk bowel patients, there was little good evidence even to support this screening – the evidence still needs to be collected. Screening everyone isn’t an option, as screening often entails risks or produces false positives which require further investigation, and these wouldn’t be appropriate for people at average risk levels. Obviously cost implications also play a major role in deciding who will be screened.