According to Belgian researchers a drug prescribed for women with advanced breast cancer would be cost-effective for treating some, but not all patients, in the early stages of the disease.
The drug, Herceptin, is a targeted therapy for breast cancer and as it kills only cancer cells it is more expensive than other treatments.
However Belgian health economists say that prescribing the drug for patients with the early stages of the disease could have a major impact on health budgets because of its high price, the duration of treatment and the number of women who would be eligible for it.
Mattias Neyt, of Ghent University in Belgium, says the product is very expensive and though it is worth its money in certain sub-groups of patients it is not for all patients.
It seems that in women with early disease who have a good prognosis with current treatments, the drug would not be cost-effective, but it would be beneficial in patients who do not respond to therapies because it could eliminate the needs for costly future treatments.
The researchers say health authorities will have to be prepared to bargain over the price of the drug and to allocate resources in their budgets to provide it to all eligible women.
Herceptin particularly targets breast cancers that express a protein called HER2, which accounts for about a quarter of women with the illness.
Recent studies have also shown it can increase survival in women with advanced breast cancer, and preliminary results from studies in early disease are also promising.
Breast cancer campaigners have been demanding a wider use of the drug, and in the UK recently Health Secretary Patricia Hewitt bowed to pressure and announced that all women diagnosed with early stage disease would be tested for suitability for treatment with the drug.
This move was prompted by the plans of a British cancer patient to take her case to receive the treatment on the nation's National Health Service (NHS) to the High Court.