Owen Sharp, of the Prostate Cancer Charity, says the Abirateron drug allows prostate cancer patients to have "a full and active life."
The drug "improves the level of pain the men have...and means they can be full participants with their family and everyday activity at a time when they are coming towards the end of their life," he says.
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Voting that had been expected on Thursday will now be held Friday instead.
Police were called in amid fears the man may have been poisioned.
Williams is charged with first-degree murder without premeditation, a probation violation and for not having a valid driver’s licence.