However, the researchers discovered that the latest trial will not be able to help majority of men and only a particular group of patients may only be able to benefit from this treatment based on the genetics of the tumours. However, numerous men who were at death's door have been on the drug for more than 18 months and show no signs of the disease'.
The world's leading expert on prostate cancer Professor Johann de Bono from the Institute of cancer research said: "We hope for a revolutionary cure, but they can't call it". This is for the first time that an immunotherapy has shown to be beneficial for men who suffer with prostate cancer that is responsible for the death of more people in the United Kingdom than the breast cancer.
With this study, George and colleagues hypothesized that black men with advanced prostate cancer would respond better to abiraterone than white men.
The results will bring hope to men such as BBC presenter Bill Turnbull, 62, who in March revealed that he had been diagnosed with prostate cancer which had spread "to the bone". "Every patient who participates in a clinical trial contributes to improving care, and all patients should have the opportunity to receive needed therapies", she said in an American Society of Clinical Oncology (ASCO) news release.
While only 5% of men in the trial saw their tumours shrink or disappear after treatment, many of those had mutations in genes involved in repairing DNA in their tumours.
The trial had 258 men with prostate cancer getting immunotherapy.
Immunotherapy has become a treatment for cancer, particularly skin and lung cancers.
They stop cancers turning off the immune system so the body can keep on attacking the tumour.
Only around 20% of cancer patients respond to immunotherapy and researchers do not fully understand why. It seems to work incredibly well for a handful of patients, have a temporary effect in others, and do nothing for the rest.
"One of the major challenges with immunotherapy is that we don't have many reliable tests to pick out who will benefit", added Professor Paul Workman, chief executive of The ICR. "This new trial has found that testing for mutations in DNA fix genes could be valuable marker of who will respond".
According to George, there is a higher risk of death from prostate cancer associated with black race than white race. Prostate cancer is treated in a number of ways, but the more extreme treatments which include surgical interventions may cause physical and psychological side effects.