Hope as even most aggressive prostate cancers respond to drug
A preliminary trial has shown that a new drug, abiraterone, can reverse even the most aggressive, resistant and deadly cancers. This could be the biggest advance in treating the disease in 60 years.
Latest data from the National Cancer Registry of Ireland revealed 2,406 new cases of prostate cancer were diagnosed in 2005, with 88% of these over 50 years of age. It estimates there will be a 275% increase in sufferers by 2020.
The disease accounts for 11% of all cancers among Irish men and over 500 deaths each year.
Almost 80% of the seriously ill men treated with the drug have seen significant improvements.
In 20% to 30% of cases, patients experienced dramatic falls in PSA — the blood marker used to test for prostate cancer — and greatly surpassed their expectations of survival.
If abiraterone continues to live up to expectations, it could be available in three years time.
A much larger study involving 1,200 patients worldwide began two months ago and will directly measure the extent to which the drug can keep people alive.
The research has led to a complete re-think about the way advanced prostate cancer is driven.
Scientists discovered 60 years ago that testosterone and other male hormones fuelled the disease. This led to treatments which either blocked the effect of male hormones on prostate cancer or stopped their production altogether.
But it was believed that when tumours stopped responding to the treatments they did not need the hormones to survive. Patients then had “hormone refractory prostate cancer”. The effectiveness of abiraterone shows this was wrong, and even apparently unstoppable cancers are hormone-driven. Aggressive prostate tumours can generate hormones of their own when the normal supply is cut off.
Dr Gerhardt Attard, one of the scientists from the Institute of Cancer Research in Sutton, Surrey, where the drug was discovered, said: “Time will be our judge, but we’re very excited about this. It is changing our understanding of prostate cancer in a way that has not been done for 50 or 60 years.”
The scientists today reported on results from 21 men who took part in the Phase 1 trial and were treated with increasing doses of abiraterone.
Their progress was mirrored by a number of other men also treated by the team, making more than 100 in total.
The men all had aggressive cancers that no longer responded to traditional hormone therapies. In many cases the disease had spread to the liver, lungs or bones. “These were not pussycats, these were tigers,” said Dr Attard. Some patients could stop taking morphine for the relief of bone pain. The findings were published online today in the Journal of Clinical Oncology.
Researchers are also looking at using abiraterone to fight breast cancer and other hormone-related diseases.
