Testing Times

14/11/2008

Blood samples donated by thousands of Guernsey women over three decades could help to save millions of lives. Nicci Martel meets the man hoping they will be key in creating a test for the early detection of breast cancer.

STORED in laboratory freezers in England at -20C are the blood samples of 11,000 Guernsey women. These little capsules, now frozen in time, were taken over a 30-year period and contain precious genetic and billogical information that could hold the key to saving potentially millions of lives.

Trying to unravel some of the answers that these samples might conceal is Dr Paul Townsend, who ­ along with a team of scientists from the University of Southampton¹s human genetics and cancer sciences division ­ is trying to find clues that could help develop an early-warning test for breast cancer.

By establishing a process by which specific biomarkers, or 'cancer fingerprints', can be identified and used to distinguish cancer cells from normal cells, the team hopes it will find a way to detect telltale signs in the blood long before symptoms of the disease appear.

If they succeed, a blood test could one day be used to identify the early onset of breast cancer. Quite simply, the earlier the diagnosis, the more likely treatment will be successful.

'Breast cancer is the most common cancer in the UK, with 44,000 new cases per year, which is soon to be more than 50,000. Your chance of developing breast cancer increases with age, but the introduction of a screening programme in the late 1980s which focuses on older women has increased the rate of detection significantly,' explained Paul, who has been working on the project for just over a year.

'But you can develop breast cancer in your 20s, 30s and 40s and that's really, really young. It can be extremely aggressive. Screening in younger women is very different. With our research, we could one day use blood, urine or even saliva samples to detect cancer and distinguish between sufferers and those without the disease.' Women who have undergone the menopause have denser breast tissue so cancer can be identified much more easily in screenings.

A long exposure to the hormone oestrogen, is thought to increase the risk of developing the disease, and is the reason why older women are encouraged to have the test regularly.

But in the Bailiwick, those under the age of 50 do not qualify for free screenings and unless a mass can be felt, they won't necessarily be given a mammogram until other diagnostic tests suggest it's needed. This delay could seriously affect a patient's outcome.

There is no sure-fire way of knowing who will develop breast cancer and who won't. Yes, age increases the risk factor, but environmental reasons, such as smoking and lifestyle, also come into play. Genetics too, has its role.

In the 1990s, it was discovered that certain variations of the BRCA 1 and 2 genes could increase the risk of breast cancer. Women can now be tested for the mutated genes, but as Paul explained, genetics still accounts for only a fraction of cases.

'About 85% of women with a close relative who has developed the disease will not develop it themselves. Even at the higher level of genetic susceptibility, only 2-5% of cases are due to genetic risk.' The samples taken in Guernsey could help Paul establish if and then why certain people are predisposed to developing breast cancer.

The collection is the cornerstone of Paul's research. He said there is no way a similar project would ever get the funding now, which makes it one of the most valuable in the world.

'What makes this an excellent collection is that the population of Guernsey is very tight and we have samples of women who at the time were healthy, but who have since developed illnesses ­ the main one we are focussed on being breast cancer,' he said.

It's a lot more difficult tracing what happens to donors who have given samples in the UK, say in Southampton for example. The population is not as stable.'

Among the blood acquired locally there are samples from around 500 women who later went on to develop breast cancer.

Paul desperately wants to identify a difference between these and the samples from women who have not developed the disease.

It lies in biological markers present in the blood of women who got cancer, absent in those who didn¹t, and it¹s these markers that could reveal a predisposition to the disease.

'Using serum proteomics ­ a type of analysis we can do on blood ­ we are hoping to narrow down which markers are relevant. Blood circulates through tissue in the body, picking up molecules along the way.

It goes through cancer cells, too. Everything is present in the blood, including proteins produced by cancer or by the body in response to cancer.

Proteomics has the power to detect these molecules. This method of analysis also requires only a tiny fraction of a sample to work ­ one tenth of a millilitre, which is then put on a chip.

Employing another method, called mass spectrometry, the different kinds of proteins can be identified.

With this process, Paul has identified 28 statistically significant biomarkers, but identifying what these proteins do is painstaking work, yielding up terabytes of information, and considering each terabyte represents 1,000 gigabytes, it's enough to make your brain implode.

He's one year into the research and believes it could be 10 before he¹s near to finalising a blood test that could identify the relevant markers, but he¹s in for the long term.

'I've got 30 years left as a paid researcher. It is a life commitment, but even over the next 10 years we can get a lot done.'  But what Paul also hopes to see during his career is a move away from the culture of secrecy that plagues the scientific community. He wants more openness among researchers, about what they're working on and what discoveries they've made.

Sharing information and techniques could, he said, speed up research and lead to quicker breakthroughs.

GEP Article by Nicci Martel 14/11/2008



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