SOME WOMEN with a particularly aggressive form of breast cancer are not receiving the best possible care, according to several leading cancer experts. One in five of the 40,000 cases of breast cancer diagnosed annually has a type of tumour that is faster-growing and more aggressive than average. Yet government guidelines mean that they are not identified until near the end of what doctors call “the cancer journey”.
The role of the human epidermal growth factor receptor (HER2) — a naturally occurring protein — in this aggressive cancer was first identified nearly 20 years ago. A decade later came the licensing of Herceptin, a drug that blocks the protein and which, so far, is available only on prescription for women with advanced cancer, at which time it has been shown to extend life by an average eight months.
Cancer specialists recently launched a campaign to persuade doctors and patients to demand that HER2 testing be carried out routinely at the time of diagnosis. “Cancer patients want to be informed fully about their disease,” says Dr David Miles, an oncologist at Guy’s and St Thomas’ Hospital in London (here patients are told if they are HER2 positive when their breast cancer is diagnosed). “Knowing their HER2 status is vital to making important life choices as well as giving patients the maximum chance of getting Herceptin at the earliest time.”
Rob Carpenter, a surgeon at Bart’s and the London NHS Trust, already tests private patients for HER2 around the time of primary diagnosis and says he is hopeful of “winning the argument” to persuade Bart’s to follow suit.
“The arguments in favour of testing as early as possible are becoming overwhelming and more hospitals will come under pressure to provide it.” Omitting the HER2 test at the initial diagnosis accounts for the huge variation in prescribing Herceptin at a later date, Miles says. The drug costs £5,000 for three months and, according to the National Audit Office, the proportion of “eligible” patients treated varies from 90 per cent in some areas to fewer than 5 per cent in others. Meanwhile, evidence presented at the European Breast Cancer Conference showed that, contrary to widespread belief, testing all women for HER2 is more cost-effective than testing only those who go on to develop advanced cancer. As Carpenter says, the test is “a matter of putting another antibody on the tissue. Against that you have extra appointments needed to carry out testing at a later stage.”
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The benefits of giving Herceptin to HER2-positive patients from the time of diagnosis is being investigated in a series of trials. The results, due in 2007, will show whether Herceptin should be prescribed to HER2-positive women in the same way as Tamoxifen, the anti-oestrogen drug, is routinely prescribed from the time of diagnosis to women whose cancer is oestrogen positive.
The charity Breast Cancer Care believes that the current priority is to ensure that all women with advanced breast cancer are aware that they have the right to be tested for HER2 status. “At present large numbers of women are being treated in hospitals that do not have properly validated laboratories,” says Emma Pennery, a Breast Cancer Care specialist nurse. “We need a proper infrastructure to test all breast cancer patients if the on-going trials show this to be appropriate.”
For Miles, however, the question is not so much about testing as about which receptors will provide the next challenge. “We are at the start of a new era of learning how to tailor drugs to the individual’s chemistry. It won’t be long before we are testing for a whole battery of receptors that will allow doctors to use therapies as guided missiles rather than as a blunderbuss, like now.”
DOCTOR’S ORDERS
Avoid having more than one sweet fizzy drink a day. Researchers at Harvard University have found that women who consume more than this have an 85 per cent increased chance of developing type 2 diabetes.
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Breast Cancer Care helpline: 0808 8006000 www.breastcancercare.org.uk