Joint Annual Research Report 2004 - The Royal Marsden

molecular genetics. Two studies, one recently completed
and the other just started, give some picture of the
types of investigation in which we are now engaging
to address these issues.
risk Celtic redhead who lives in a temperate country.
The Celt who sunbathes on the beach in Queensland,
Australia, however, should not be so sanguine and the
use of targeted prevention measures, such as protective
sunscreens, is obvious.
Most genetic risk factors for cancers are not
outwardly perceptible, however, and therefore to
ascertain them requires genetic testing in the laboratory.
Such testing is now becoming practical on a large scale,
so that the opportunities for studies of epidemiology
and genetics in combination are opening up rapidly.
Studies of cancer causation
that combine epidemiology
and molecular genetics
The Institute’s Section of Epidemiology, in collaboration
with the Section of Cancer Genetics and with the
Breakthrough Toby Robins Breast Cancer Research
Centre, is setting up large-scale epidemiological studies
of cancer causation that combine epidemiology and
Causes of brain tumours
Brain tumours are a fairly common type of cancer, and
the most frequent of them, gliomas, are often rapidly
fatal. We know very little of their causation or how to
prevent them. The only known non-genetic cause is
exposure to ionising radiation (eg X-rays), which
accounts for very few cases. There is anxiety among
some members of the public, however, that radiofrequency
radiation from mobile phone use might be
a cause.
We are investigating the causes of brain tumours
using a study design called a case-control study. This
compares exposures, behaviours and genes between
patients who have brain tumours (cases) and people
who do not have this condition (controls). We have
collected data over the past 4 years from over 1,000
brain tumour patients, plus control patients, to search
for environmental and genetic causal factors. We are
now analysing the data that have been collected, both
within our own study and in combination with data
from other similar studies from other countries (in
order to gather even larger numbers).
Causes of breast cancer
The second example is a study approaching the problem
of cancer causation in a different way: starting with
people who have different levels of exposure to
potential causes and then following their subsequent
risks of breast cancer over time. This study, the
Breakthrough Generations study, is recruiting more
than 100,000 women to investigate, over time, whether
those who have greater levels of particular factors
(eg more exercise or greater radiation exposure) have
greater (or lower) risk of breast cancer than those with
less or none of these factors, and how this interacts
with their genetic predisposition. The study was publicly
launched in September 2004 and is progressing very
encouragingly. Over 10,000 women contacted us by
email or telephone in the first 24 hours after the launch
to express interest in joining.