The European Union has approved the use of the breast cancer drug Herceptin for use in patients with an early stage of the aggressive HER2-positive type of breast cancer.
Drug company Roche says the approval follows the results of a study which showed Herceptin reduces the risk of the cancer returning by 46 percent compared to chemotherapy alone.
Herceptin already has approval in the EU for the treatment of advanced HER2-positive breast cancer.
Herceptin works by blocking the HER2 protein produced by a gene with a particularly aggressive cancer-causing potential.
Around a fifth of breast cancers are HER-2 positive.
The new approval of Herceptin means its use can be extended to a large number of mainly younger patients.
Campaigners have been demanding Herceptin to be made available for women with less advanced breast cancer and in the UK the NHS has promised it will fast-track its appraisal of the drug.
Herceptin has been the subject of high profile legal battles by women seeking access to the drug.
A year's course of the drug costs around £20,000 and it has become a 'post code lottery' in the UK with some health authorities supplying it while others have denied it to women, hence the court cases.
Health Secretary Patricia Hewitt intervened in the debate last October saying NHS bodies should not withhold the drug on cost grounds from patients whose doctors had recommended it.
There are some concerns however that Herceptin's effectiveness is over-rated but many women with this type of cancer welcome the news.