US researchers have made a discovery that they hope will enable them to ensure that only patients likely to benefit are given chemotherapy.
The study by the University of Michigan Comprehensive Cancer Center determined that women whose breast cancer expressed a protein called HER-2 were most likely to benefit from adding the drug Taxol to the chemotherapy regimen.
Women with oestrogen-fuelled tumours, meanwhile, did not get any benefit from Taxol.
Around 15 to 20 per cent of breast cancers express HER-2, while up to three-quarters are oestrogen-receptor-positive.
Senior study author Dr Donald Berry said: "Determining who doesn't need chemotherapy and can be spared some portion of toxic therapy is one of the biggest issues facing breast cancer today."
He continued: "In oncology, we are very good at adding therapies to a patient's regimen, but we are not as confident subtracting treatment. Hopefully, in time, we'll be able to limit therapies to those that will truly benefit from the additional regimen."
The research appears in the October 11th edition of the New England Journal of Medicine.
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