The court victory of British woman Barbara Clark to be treated with the breast cancer drug Herceptin, means that now more than 100 breast cancer patients in Cornwall and Devon could soon be prescribed the drug.
Cancer charity CancerBACUP says the victory is a "breakthrough moment" and that other health authorities should follow the decision made by South West Peninsula Health Authority (SWPHA).
Herceptin costs up to £30,000 a year for each patient and is already widely used for patients with advanced breast cancer or those who are terminally ill.
Health managers have expressed concern that said it could pose financial problems.
According to Dr Jim O'Brien, director of public health at SWPHA, the cost of providing the drug will be approximately £4m which will be divided between the 11 primary care trusts in Devon and Cornwall and included in 2006/07 drug budgets.
But following the 5 October victory of former nurse Ms Clark, it was announced all women with early-stage breast cancer in England would be tested to see if they were eligible for the drug.
Tests have already shown the drug could greatly extend sufferers' life expectancy, but it had not previously been approved for use on women in the early stages of the illness.
The SWPHA decided to allow treatment on the condition that the treatment is supported by the patient's clinician, and that the patient herself is willing to receive the drug.