Examination of Witnesses (Questions 178
WEDNESDAY 11 JUNE 2008
Professor Peter Furness, Dr John Crolla, Dr Imran
Rafi and Professor Stephen O'Rahilly
Good morning to all of you and thank you for coming. Welcome to
the panel that have come in their spare time to give evidence
to us today and a particular welcome to Professor Stephen O'Rahilly
who I know was called in at the last minute. My first question
relates to translation of the genomic information and genomic
science. We have had differing views given to us on this. On the
one hand we have the view that DNA and RNA-based tests are already
being used in clinical medicine and on other hand we are told
it will take years before many of the genomic science knowledge
will be translated into clinical medicine. Which bit is true,
and how fast is the science moving so that we are able to plan
its translation into clinical medicine? The memorandum from the
Royal College of Pathologists states that there will be an exponential
increase in genomic tests. What are the cost implications of all
of this? Who is actually monitoring or making pronouncements about
which tests are good and which tests are not so good?
Professor Furness: I am Professor Peter Furness.
I am Vice-President of the Royal College of Pathologists and President
Elect. I am a histopathologist by training, but I have also been
heavily involved in a College initiative looking at how we evaluate
new diagnostic investigations. You have just asked a whole series
of questions, all of which have really very complicated answers.
Simplify it for us!
Professor Furness: You started with what was
given to us as question one on the list of possible questions,
which concludes, "Are these differences disease specific?
Or are they a reflection of the different types of genetic tests?"
The answer is both. The word exponential came from a discussion
that we had with Professor Finbar Cotter, who is a hematologist,
who has described in his laboratory an increase of three-fold
in the number of genetic tests being undertaken in the space of
two years. Elsewhere the increase has been less dramatic. I know
my colleague Dr Crolla has some information about the increases
annually of about 20 or so per cent in a different area. The problem
is that this is so enormously broad. Leukemia is mentioned as
an area where genetic tests of one sort are already very important
because in some types of leukemia there are consistent, reliable
and relatively straightforward changes that you can look for.
Other types of cancer are much more variable. For example, we
have recently seen developments in expression profiling which
give improved prognostic information in breast cancer, a common
cancer compared to leukaemia. I have already mentioned a relatively
simple and long-standing set of genetic investigations for leukaemia
and compared that to a technically completely different investigation
looking at what the genes are doing and how they are being expressed.
There was a good example in Nature a few years ago which
took what we thought was a single disease entity, large Bcell
lymphoma, which we thought had a very unpredictable response to
treatment and demonstrated that by looking at the gene expression
of these tumors you can split them into those that will respond
and those that will not. That was in 2002 and it is still not
in routine practice. I have only been talking about acquired mutations
in tumours. I have not even been addressing the underlying changes
which I think stimulated this Select Committee's inquiry, which
are to do with population-wide screening of an individual's inherited
genome, I have been talking about mutations in that genome. There
is another question in your list that is talking about cervical
cytology, which I think is actually related to assessing the genome
of viruses rather than humans. You have in here such a vast spread
of potential in a whole lot of different areas that the Select
Committee is going to have to be careful to pick out the different
elements and recognise that there are advantages to be gained
in a whole lot of different areas as a result of different technologies.
Saying "exponential" is probably mathematically inaccurate
because it is going to be very jagged. In some diseases there
is going to be a development that becomes very valuable very quickly
and in others it is going to take longer and then suddenly there
is a breakthrough, but that is the nature of the whole process.
You asked a question about the expense. That is immensely difficult
to discuss, but the costs vary depending on the different tests
that are required. At the moment I am told that sequencing someone's
entire genome can cost about £10,000, but extrapolation suggests
that that will probably come down to £1,000 within a few
years. We are already in a situation where I am told if you want
to sequence 10 genes from one individual economically you may
as well sequence the whole thing. There is a very rapid change.
The costs will come down, but they will remain substantial if
you have large numbers of patients compared to what we use at