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.
In the research by Neyt and his colleagues an economic evaluation of the drug was carried out.
It was found that prices for the drug varied from 928 Euros ($1,096) per 150 mg vial in Norway to 647 Euros in Belgium and 595 Euros in England.
According to the researchers there are in Belgium more than 6,600 cases of breast cancer a year.
Of these about 45 percent would be in the earlier stages of disease in which the drug would be used and about a quarter of them would have the type of disease that responds to Herceptin.
Providing the drug to all these patients would cost about 34,000 Euros per patient or a total of 25.5 million Euros.
Neyt and his team advise that countries should not rush to prescribe the drug before they calculate the implications of re-allocating resources and should bargain over the price of the drug.
Neyt says the aim should be to arrive at a price that results in cost-effective treatments, which budgets can bear, even if the drug is provided for a large number of women.
The research is published in the Annals of Oncology.