Drug that helps women survive breast cancer can also prevent the spread of prostate cancer in men, according to a new study

A A flagship drug that improves the survival of women with breast cancer can block the progression of prostate cancer in humans, revealed a landmark study.

British trials suggest that treatment – which is also used to treat ovarian cancer – could benefit 4,000 men a year, delaying the time when the disease will become fatal.

Charities said they were "very excited" about the results of the Cancer Institute's study and the Royal Marsden Hospital.

The drug, called olaparib, is already funded by the NHS for women with ovarian cancer fueled by mutations in the BRCA gene and will soon be screened for its use in breast cancer.

The damaged DNA has been dubbed "the Jolie gene" after Hollywood actress Angelina Jolie, who has undergone a double mastectomy and an ovary removal to reduce her risk of cancer.

Research has now shown that treatment is effective in 80% of men with prostate disease who have the same mutations.

Even though the patients were in advanced stages of the disease, the drug blocked the disease for an average of eight months. And one in three has not progressed for more than a year.