Medics said the treatment - from a class of drugs called PARP inhibitors - could become the first to use gene targeting to fight prostate cancer.
Drug which helps woman survive breast cancer can also stop prostate cancer spreading in men, new study finds
Summary: A pioneering drug that boosts survival for women with breast cancer can stall progression of prostate cancer in men, a landmark study has found.
The British trials suggest the treatment - which is also used to treat ovarian cancer - could benefit up to 4,000 men a year, delaying the moment when the disease becomes deadly.
Charities said they were “very excited” about the findings from the study by the Institute of Cancer Research (ICR) and the Royal Marsden Hospital.
The drug, called olaparib, is already funded on the NHS for women with ovarian cancer fuelled by BRCA gene mutations and will soon be reviewed for its use for breast cancer.
The damaged DNA has been dubbed “the Jolie gene” after Hollywood actress Angelina Jolie, who underwent a double mastectomy and ovary removal to cut her cancer risk.
Research has now found that the treatment worked in 80 per cent of men with prostate disease who were suffering from the same mutations.
Even though the patients had advanced disease, the drug stalled the disease for an average of eight months. And one in three were free of progression for more than a year.
Every year around 47,000 men in the UK are diagnosed with prostate cancer, causing 11,000 deaths.
The study screened the tumours of 592 men, and found more than one in four had alterations in one or more genes linked to damaged DNA, most commonly because of BRCA mutations.
Overall, 47 per cent of men with defects responded to the drug, delaying progression for an average of almost six months.
The best results were in those with a BRCA mutation, with response rates of 80 per cent.
RStudy leader Professor Johann de Bono, from the ICR, said: “Our study is exciting because it shows just how powerful genetic targeting and precision medicine can be. We have shown that by testing for DNA repair mutations we can select those patients with a high chance of responding welland for a long time to the targeted drug olaparib.”
“Overall between one in three and one in four men with lethal prostate cancer respond – those with DNA repair defects. That means 3,000 or 4,000 men a year in the UK would benefit from these drugs in the UK,” he said.
“We were delighted to see such strong responses in men with very advanced cancers, where BRCA mutations and other faults in DNA repair genes were present within their tumours. The next phase of the trials is now under way and, if the results look as good as we hope, we should see olaparib starting to reach the clinic for men with prostate cancer in the next couple of years.”
In rare cases, men had survived on the drug for 10 years.
“We are certainly seeing many men taking them for more than a year,” he said.
The study examined progression of disease.
But Prof de Bono said he was confident they will show improvements in survival.
Professor Ruth Plummer, from Cancer Research UK, said: “These promising results suggest that more patients with a wider range of tumour types may benefit from PARP inhibitors than previously thought.
“As we move towards an era of personalised medicine, homing in on specific genetic faults in prostate tumours could provide more options for certain men with the disease. Larger clinical trials are now needed to see if this approach saves lives.”
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