Why healthy women are taking breast cancer drugs
01:57 GMT, 20 March 2012
Last summer, just after her 35th birthday, Charlotte Stockton began a course of tamoxifen, the drug used to treat breast cancer.
She was perfectly healthy and had no signs of cancer, but Charlotte decided to take the drug in a bid to protect herself from the disease that killed her mother at the age of 44.
‘I was 15 when my mother died,’ says Charlotte, from Manchester, who works as a researcher in the NHS.
'My mother's death had a huge impact on me. I was conscious I had an increased risk of developing the disease,' said Charlotte Stockton
‘After she had a mastectomy, the cancer returned aggressively and she was very ill for a year before she died.
‘My mother’s death had a huge impact on me. I was conscious I had an increased risk of developing the disease.’
One in ten women in Britain will develop breast cancer, and studies have shown a strong genetic link. It is the most common female cancer in the country, with 45,000 diagnoses and 11,000 deaths from the disease each year.
Tamoxifen was first used for breast cancer in 1969 at the Christie Hospital, Manchester.
The drug is given to patients following initial treatment, which can involve surgery, chemotherapy and radiotherapy.
Charlotte on holiday with her mother – the year before her mother died
It works by blocking the uptake of the hormone oestrogen by cancer cells, stopping them multiplying and preventing the cancer coming back.
A patient takes tamoxifen, usually in pill form, for about five years after their treatment, and the drug has been partly credited for the dramatic fall in deaths from the disease.
But in the Eighties, scientists started to notice that in women taking tamoxifen, the incidence of new breast cancers in their other breast halved.
They speculated that tamoxifen might have another role — preventing cancer from occurring in the first place. It is thought the drug may bind to oestrogen receptors in cancer cells that are otherwise destined to progress.
Subsequent studies have shown it can prevent up to 40 per cent of breast cancers in high-risk women. The drug has been approved by the U.S. Food and Drug Administration for the prevention of breast cancer.
Tamoxifen is not yet licensed for this use in Britain and Charlotte is one of a number of women taking part in the country’s first trial of tamoxifen as a preventative.
In the trial, at the Genesis Prevention Centre in Manchester, 200 women aged 33 to 46 will take a daily tamoxifen pill for five years.
‘All women who attend our family history clinic have an increased risk of developing breast cancer,’ says Professor Tony Howell, who is leading the research team.
‘Most have at least two first-degree relatives (parent, sibling or child) with the disease, and some may be carrying the BRCA1 or 2 gene mutation, which is linked to breast cancer.’
Half the women will be allocated tamoxifen and the other a placebo, and all will have regular check-ups and mammograms.
Professor Howell is hopeful the trial will provide positive evidence that may lead to the introduction of tamoxifen as a preventative drug in Britain.
Professor Jack Cuzick, a leading cancer specialist who is working on the trial, believes the research holds great potential.
‘Though it is obviously too early to say how successful the trial will be, I am excited by what the outcome will bring.
‘Women who are at risk of getting breast cancer and who have a strong family history must be scared and worried about developing it.
‘So to know this trial exists will hopefully help relieve some of their anxiety and fear. It is a hugely important development.’
Though there is no other history of breast cancer in her family and she has not been tested for the BRCA1 or 2 genes, Charlotte says that as she got older, she became more and more worried about her health.
‘I have had two breast lumps checked out, but thankfully on both occasions it was a benign lump and nothing to worry about,’ she says.
Because of Charlotte’s health concern, her GP referred her to the Genesis centre, where she learned about the study.
‘I want to do all I can to minimise my risk of getting the disease. I can do more exercise, watch my weight and be breast aware, but being part of this clinical trial means I am doing everything I can to protect my health.’
'The only side-effect I have experienced is a few mild hot flushes, which have been fine to deal with,' said Charlotte of taking tamoxifen
After an initial mammogram and gene test, Charlotte was told she could change her mind at any point during the trial, and that there were doctors, nurses and a hotline available at all times should she have any concerns.
Now over halfway through the first year of the trial, Charlotte will be given the option to continue the drug for another four years at her annual visit to the clinic in June.
Though the trial has been approved by an ethics committee, tamoxifen is yet to be licensed in the UK as a preventative drug because of the concern that otherwise healthy women are risking the side-effects of a drug when they have no disease.
These can include hot flushes, mood changes and joint pain.
Charlotte decided these were worth it if she had a chance of remaining cancer free.
‘When I was told about the trial, I was warned in detail about the possible side-effects that I could experience, but I was confident the drug was very safe to take as I know it is so widely used.
‘I was obviously nervous at the start, but the only side-effect I have experienced is a few mild hot flushes, which have been fine to deal with and don’t last long.’
Consultant surgeon Lester Barr, who heads the Genesis Appeal, believes the concern over side-effects of the drug is the only thing standing in the way of it being licensed in the UK, as it already is in the U.S.
‘If we can identify after a year of taking the drug whether or not it is working in any individual, we can stop prescribing it to women for whom it is not working.
‘Those for whom it is working can continue on it for the trial’s full five years.
‘This approach spares the side-effects for women who are not receiving the benefit.
‘The idea is to see if we can reduce the number of predicted cancers over the following ten years and balance that against the side-effects experienced.
‘For those taking part in the trial, it is a nerve-racking but exciting time. I have found that these women are highly motivated to help because they’ve witnessed a close relative suffer the disease.’
As Charlotte says: ‘My mother’s death at such a young age was tragic.
'The fact I’ve been offered the chance to do something that will hopefully prevent me suffering the same way she did is incredible.’
The TAM-Prev study is being funded in a project under the NIHR Research for Patient Benefit (RfPB) programme and the Genesis Breast Cancer Prevention Appeal, genesisuk.org