The pill that uses the patient's genes to target tumors will revolutionize the treatment of prostate cancer

The first personalized prostate cancer drug is expected to revolutionize treatment and prolong the lives of thousands of people.

A daily pill using the genetic makeup of a patient to weaken the defenses of a tumor would work in 80% of men with certain genes.

Experts estimate that treatment – already available for ovarian cancer – could benefit 4,000 men each year, delaying the time when the disease will become fatal.

British research, presented at the world's largest cancer conference, paves the way for the first personalized medicine – or "precision" – for prostate cancer.

These target cancers based on genetic makeup rather than the "one size fits all" approach of chemotherapy and hormonal therapy.

The Daily Mail is campaigning for improved treatments and diagnosis of prostate cancer, lagging behind other diseases such as breast cancer.

Despite the rapid progress of other types of cancer, the number of British men died from prostate cancer is increasing and now stands at 11,800 per year.

Scientists led by the London Cancer Institute followed 100 men with advanced prostate cancer who had failed to fight the disease with other treatments.

The new drug, called olaparib, delayed disease progression in those who responded on average for 8.3 months. For 35% of patients, the cancer has stopped spreading for more than a year.

The pill is not a cure – and until now it only freezes cancer – but researchers are hopeful that new tests also show that it can give dying men additional years. Professor Johann de Bono, head of the study, spoke at the annual conference of the American Society of Clinical Oncology in Chicago: "Our study shows how powerful genetic targeting and precision medicine can be. By testing for DNA repair mutations, we can select patients with a high risk of reacting well to olaparib.

"Overall, between one in three men and one in four men with fatal prostate cancer respond: this means that 3,000 to 4,000 men a year in the UK would benefit."

In rare cases, he said that men had survived with this drug for ten years. "We see a lot of men taking them for over a year," he said. The experts are excited about the results – and four more important tests are underway.

If, as expected, these results are successful, the drug could be used by the NHS within two years. The treatments exploit a weak defense of cancer cells to kill a tumor without harming healthy cells. The drug, which costs £ 3,550 a month, was made available to the NHS for ovarian cancer three years ago and is expected to be used for breast cancer soon.

But it was only thanks to the persistence of the Bono professor – and funding from charitable organizations – that the same tests were launched for prostate cancer.

"[It] is not a priority for pharmaceutical companies – it's really Cinderella, "he said. The experts welcomed the results. Professor Ian Davis of Melbourne Monash University said, "The treatment of the prostate is years behind in targeted treatments. Treatments such as olaparib seem to be the best solution to close this gap. "

Paul Villanti, of the Movember charity, said: "It is very exciting to see the existing treatments reviewed for the benefit of men."