<sod >Lead author Dr Joseph Sparano said: 'Our study shows that chemotherapy may be avoided in about 70 per cent of these women when its use is guided by the test, thus limiting chemotherapy to the 30 per cent who we can predict will benefit from it.'< eod>< sod > Lead author Dr Joseph Sparano said: 'Our study shows that chemotherapy may be avoided in about 70 per cent of these women when its use is guided by the test, thus limiting chemotherapy to the 30 per cent who we can predict will benefit from it.' Chemotherapy typically costs PS4,500 ($6,015) per patient, so the findings could save money for both the NHS and tens of thousands of women battling the cancer in the US.< eod>