Risk Assessment: Breast Cancer, Prediction and Screening

Doctors, survivors and supporters again converged in a basement lecture theatre in Bloomsbury for the second event in the 'Breast Cancer: Chances, Choices and Genetics' series organised by the Progress Educational Trust, bringing together experts and interested parties for an evening of discussion. On the cards this night: prediction and screening.

The panel boasted patient, clinical and research expertise. Each speaker took to the lectern in turn to introduce their topic. Wendy Watson started with a sadly familiar story: after both her mother and grandmother were struck down early with breast cancer, investigation revealed that a number of other relatives had also developed the disease. Hereditary causes of cancer were less well understood at the time and, rather than waiting for the cancer to strike, hoping to catch it early enough to be of use, Ms Watson underwent an elective risk-reducing double mastectomy in 1992, becoming one of the first women in the UK to do so.

In addition to campaigning on behalf of cancer awareness and prevention, Ms Watson went on to found and direct the National Hereditary Breast Cancer Helpline, providing information to people who are worried about the risk of hereditary breast cancer.

The next speaker was Paul Serhal, one of the first doctors in the UK to use PGD to screen for the presence of a mutated version of the BRCA1 gene, known to greatly increase the risk of breast cancer. He explained that it was contentious at the time to screen embryos for genes that increase susceptibility for a disease, instead of outright causing a disease.

Stephen Duffy, professor of cancer screening, said the biggest difficulty in detecting and preventing cancer was variety. 'Cancer' encompasses a number of diseases with different causes and risk factors, he explained, and screening for them all or knowing how to treat them can get incredibly complicated - even when we know a lot about a great many risk factors, this doesn't necessarily help us know who will get cancer. 'Strong risk factors are rare, common risk factors are weak', he said.

Professor Duffy was, however, largely positive about our current use of mammograms to screen at-risk age groups, which (in spite of the risk of overdiagnosis and false positives) prevent a great many deaths from breast cancer.

The final speaker was Professor Klim McPherson, who was drawn to work on breast cancer after witnessing how it affected his family. As an epidemiologist, Professor McPherson studies the statistics of breast cancer on large, population scales, measuring what the risks are and what changes them.

Although his particular work involves measuring the effect of hormone-based medicines on cancer risk, his contribution to the discussion was about risk more generally and how knowing the risks doesn't always change matters. For example, while his work found that long term hormone replacement therapy (HRT) can double the risk of breast cancer, that doesn't mean that HRT should not be used: just that people should be aware of the risks.

Similarly, some of the best known risk factors relate to the onset of menses and giving birth, leading Professor McPherson to joke that '...the thing to do is start having periods as late as you can, [and then] as soon as you get periods, have a baby'. Even when we know the risks, it doesn't always translate to practical medical advice.

What really struck me on this occasion was the interwoven nature of the breast cancer community. It's more than just the impressive turnout of breast cancer patients, doctors, advocates and campaigners at these events, but how they link together.

I first noticed this at the previous event in the series, when it turned out the cancer researcher friend I attended with was partially funded by the charity run by one of the speakers, Baroness Delyth Morgan. This latest event went one further. Not only was one of the previous event's speakers — BRCA1 carrier Kerry Andrew — in the crowd and contributing to the discussion, but she cited Wendy Watson as a personal inspiration, whose work in raising awareness helped her decide to undergo her own double mastectomy. What's more, the doctor that Ms Watson was referred to when seeking risk-reduction surgery turned out to be none other than Professor Gareth Evans, another of the previous event's speakers.

Much like the earlier event, the most lively contributions were made after introductory presentations, when the discussion was thrown open to the floor. Once again it was an informed, engaged crowd, from a variety of backgrounds, ably chaired by the GP and health writer, Dr Ann Robinson.

It seems that the tone of the discussion flickered between stark realism and justifiable optimism. On the negative side, the unfortunate statistics show that this terrible disease remains a large burden for a great many families. 'The chances of dying of breast cancer are small', Professor McPherson told us, 'but the chances of getting breast cancer are big'.

On the other side of the equation, the optimism stems from the notion that current screening and prevention programmes and technologies prevent a great many deaths and will continue to be refined.

Have your say about breast cancer and genetic testing, by taking a minute to complete the Breast Cancer Poll on BioNews here.