Hundreds of thousands of women with early stage breast cancer are set to be spared chemotherapy, following the publication of a groundbreaking study showing that they derive no benefit from the gruelling treatment.
About 250,000 women in Europe, North America and Japan are diagnosed each year with the most common type of breast cancer and the vast majority are treated with chemotherapy after surgery, subjecting them to toxic side-effects such as nausea, hair loss and anaemia.
But a trial of more than 10,000 patients suggested that 70 per cent of women should not be given chemotherapy because it does not improve their survival prospects. They can therefore be treated with hormone therapy alone, which is far milder.
The study found that oncologists could use a genetic test called Oncotype DX — made by Genomic Health, a Californian diagnostics company — to predict accurately which women would benefit from chemotherapy. Some doctors already use the test, but the proportion of patients who can forgo the poisonous cocktail of drugs is far greater than previously thought.
Results of the study, the largest breast cancer treatment trial to date, were presented at the annual meeting of the American Society of Clinical Oncology in Chicago, where doctors hailed the results as “practice changing”.
“This will have an immediate impact on the treatment of these women,” said Joseph Sparano, an oncologist at Albert Einstein Cancer Center in New York, who led the research. “The current guidelines have made doctors use chemotherapy without a high level of evidence, but for most patients there is no benefit.”
Dr Sparano predicted the findings would quickly be incorporated into the advisory guidelines that oncologists use to determine how to treat patients. The Oncotype DX test analyses 21 genes to predict whether a patient can afford to be spared chemotherapy.
Following the research published on Sunday, those with scores that are “low” or “intermediate” — accounting for almost three quarters of patients — are likely to be counselled against chemotherapy, while a smaller group of high risk patients would be advised to undergo the treatment.
The study enrolled patients with the most common form of the disease, which accounts for almost half of all cases: oestrogen receptor positive, HER2 negative breast cancer that has not spread to the lymph nodes.
The breakthrough is the latest example of how “precision medicine” is transforming the treatment of cancer, as doctors use sophisticated genetic testing to match patients with the appropriate drugs or to spare them the pain of unpleasant therapies altogether.
In the UK, Genomic Health has been sparring with the National Institute for Health and Care Excellence (Nice), the country’s cost watchdog. In 2015, Nice recommended that NHS oncologists use the Oncotype DX test but in a draft document in January this year it signalled its intention to overturn that decision. At the time, Genomic Health responded to the proposed reversal by warning the move would represent a “significant step back” in cancer care.
Then in April Nice changed its mind and provisionally recommended again that the NHS should use Oncotype DX and two other tumour profiling tests. Final guidance is due in September.
Speaking after the study was published on Sunday, Steve Shak, chief medical officer, said: “This is a once-in-a-decade trial, and it is critical that Nice take the data into account. It shows, unequivocally, that there is no benefit to chemotherapy for these patients.”
The list price for Oncotype DX is around $4,500 in the US and £2,500 in the UK, although the NHS pays a subsidised price. Dr Shak said the test represented a significant saving over the cost of giving people unnecessary chemotherapy and treating the associated side-effects.
Baroness Delyth Morgan, chief executive of Breast Cancer Now, said: “We hope these exciting findings will now be reflected in Nice guidance to help patients and their doctors in their treatment decisions . . . It is crucial that Nice has the opportunity to consider these results as soon as possible.”
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