Changing the order that chemotherapy drugs are given to breast cancer patients before surgery makes treatment much more effective, according to trial results presented at the American Society of Clinical Oncology (ASCO) conference in Orlando on Sunday.

Researchers from Cambridge have carried out a large phase III clinical trial, funded by Cancer Research UK, looking at women with large tumours in the breast. These women usually have a more aggressive form of the disease and need chemotherapy to reduce the size of their tumour before surgery.

They found that if Taxol or combinations of taxanes are given in the first course of treatment – followed by epirubicin and cyclophosphamide for the second round – breast tumours are more likely to have completely disappeared at the time of surgery.

Compared to the standard sequence of treatment – epirubicin and cyclophosphamide followed by Taxol or taxane combinations – patients’ response to treatment improved by 33 per cent.

The trial, called Neo-tAnGo, recruited over 800 women from centres across the UK who had tumours larger than two centimetres. One group of women received the changed order of chemotherapy drugs and the second group had the standard order of treatment.

Dr Helena Earl, from Cambridge University and chief investigator on the trial, said: "Having chemotherapy before surgery is important for women who have larger tumours, which often means they have a more aggressive form of the disease. For many women, shrinking the tumour before it is removed could be the difference between having a mastectomy and saving the breast with a small amount of surgery.

"There could be big advantages from reversing the standard sequence and giving the Taxol or taxane combinations first. A further advantage is that Taxol and similar taxanes can be more easily combined with some of the newer breast cancer treatments like Herceptin and Avastin.

“We are very grateful to all the patients who took part in this research. It will help us work out which tumours respond best to which treatment and is part of our larger programme of research in Cambridge to tailor treatments better to individual cancers."

As part of the trial the researchers also looked at whether adding gemcitabine to standard chemotherapy before surgery had any benefit. They found that there was no improvement in the way patients responded to the treatment which confirms results of an earlier trial called tAnGo, which reported its first findings at the ASCO meeting last year.

Kate Law, director of clinical trials at Cancer Research UK, said: "These results are excellent news for women with large tumours. They provide another clue to finding the best type of treatment for more aggressive forms of breast cancer and may lead to better survival in the future."