A breast cancer test capable of sparing countless women the ordeal of chemotherapy might possibly be available in the UK this year.
The test costs just 120 pounds a time and can accurately predict whether a tumour is likely to return after it has been surgically removed.
At present around half of the 48,000 women diagnosed with breast cancer each year undergo chemotherapy after surgery to reduce the chances of the illness returning.
But British scientists behind the test suspect that many do not need to have this debilitating treatment as their tumours are 'low risk' and unlikely to recur.
They estimate that the test, called ICH4, could pick out between 4,000 and 5,000 women every year who would not need chemotherapy.
Chemotherapy can last up to six months and normally brings on debilitating side effects including nausea, hair loss and extreme fatigue. It also leaves some patients infertile.
Doctors decide whether a woman should have the treatment by looking at the size and characteristics of the tumour.
But in around a quarter of all cases, it is almost impossible to predict whether the tumour is high or low risk.
In a new study, scientists at the Royal Marsden hospital in London found that the test picked out half of women with these unpredictable tumours as actually having low-risk cancer.
The test was used on 101 women including 26 who were categorised as being at "intermediate" risk. But the test found that 15 of these women were actually at low risk and therefore did not need chemotherapy.
"This is a simple, cost-effective test," the Daily Mail quoted Mitch Dowsett, from the Breakthrough Breast Cancer Research Centre at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, s saying.
"This new research suggests many additional patients could be classified as at low risk, and therefore avoid chemotherapy and its toxic side effects.
"This could make a big difference to those patients, and also save the NHS money. It is currently being assessed by the National Institute for Health and Clinical Excellence (NICE) for widespread use through the NHS.
"We need to extend this research with clinical and laboratory colleagues at other centres, but if the results continue to be positive then this test could be of considerable value to patients," Dowsett said.
The test measures levels of ER, PR, HER2 and Ki67 proteins in the tumour once it has been surgically removed. This allows doctors to gauge more precisely the likelihood of the cancer returning.
NICE, the drugs rationing body, is expected to make a decision in October on whether it should be available on the NHS.
But previous studies have found it is just as effective as far more expensive procedures on the market, including an American analysis called Oncotype DX, which costs 2,500 pounds per patient.
The study has been published in the British Journal of Cancer.