Scientists have found that a combination of drugs regularly given to breast cancer patients destroyed tumours in a shorter period of time.
Less exposure to chemotherapy would reduce the risk of side-effects, such as hair loss, nausea and, in some cases, permanent infertility.
The research team had already proven the effectiveness of using doxorubicin, a chemotherapy drug commonly given to stop tumour growth, and zoledronic acid, a well-tolerated treatment given to protect bone in advanced breast cancer.
Senior lecturer Dr Ingunn Holen and her team, funded by Breast Cancer Campaign, treated a group of mice with the combination every week for six months and another group for six weeks.
The International Journal of Cancer said that in both groups tumours shrank from their original size and became barely detectable.
Dr Holen said: 'These findings are very promising. Clinical studies in patients are now needed.'
Around 45,000 women in Britain each year are diagnosed with breast cancer.
Daily Mail has contributed to the report.