AstraZeneca’s oncology drug Zoladex (goserelin) extends the life of patients suffering from prostate cancer, according to the details of an independent study revealed by the Anglo-Swedish company.

The trial, organised by the Radiation Therapy Oncology Group, involved nearly 1,000 patients with locally advanced prostate cancer and is “one of the longest and largest studies of its type,” the company noted. The 10-year study, which included 977 patients with advanced prostate cancer, showed that 49% of men treated with Zoladex after radiation therapy were alive 10 years later, compared with 39% who waited until their tumours got worse before taking the drug. Furthermore, only 22% who took Zoladex immediately after radiation saw their tumours increase in size, versus 38% who delayed taking the treatment.

Zoladex reduces levels of testosterone in men and oestrogen in women, and is also used to treat hormone-dependent breast cancer in pre-menopausal women. It had sales of $917 million last year.

Dr Colleen Lawton of the RTOG noted: “Prostate cancer is the second most commonly diagnosed cancer in men in many Western countries, it is the most common male cancer in the US and the incidence of the disease is increasing… these data provide new hope for long-term survival.”

Not everybody was so impressed, however, and Martin Eden, an analyst at Eden Group, said that the study “won’t alter anything dramatically,” in financial terms, as Zoladex may lose patent protection this summer.