Irish cancer specialists yesterday welcomed a breakthrough on a new cancer drug but cautioned against predictions that it would cure the disease in two years. The new treatment had been shown to stop all kinds of cancers in mice, but that did not mean it would work on humans.
Dr John Crown, chairman of the Irish Clinical Oncology Research Group, described it as a very exciting development. This area of research into the disease, he said, was one of the most interesting in oncology in recent years. "As a researcher I am tremendously excited and I hope it works out. It is very exciting to see some of the lines of research converging and being ready for human testing. I sincerely hope that the clinical trials get organised quickly."
However, he said, a number of previous treatments looked very promising in animal experiments but have not worked in humans. "I have heard of many cures for cancer over the years which did not pan out. While we get very important leads from these experiments only careful methodical clinical trials in humans will answers the question with validity," said Dr Crown, a consultant medical oncologist in St Vincent's Hospital, Dublin. Harvard professor and researcher at Boston's children's hospital, Dr Judah Folkman, the man behind the breakthrough, was urging caution about his discovery of a new drug combination which trials have shown wipes out all cancers in mice. It was "very promising", he said, and could have potentially dramatic effects on human cancers.
"But we have to be careful with expectations," he warned. "We know the proteins work on mice, but the important thing is determining whether they work on people." The drugs - angiostatin and endostatin - work by cutting off the blood supply to tumours. Given intravenously to mice, they have caused all kinds of tumours to shrink and disappear. The breakthrough in what are known as anti-angiogenesis drugs comes after three decades of research, which began when Dr Folkman reasoned that tumours could not grow or spread without a blood supply which developed with them.
Dr David Fennelly, consultant medical oncologist in St Vincent's Hospital, Dublin, described it as a "very important breakthrough", and there was a very strong possibility it would be of value in managing cancer in humans. However, he believed it was up to five years away from clinical application on Irish patients.
It signalled a new approach to the treatment of cancer, he said. To date, standard chemotherapy treatment has focused on the inhibition of cell replication and growth "which has been somewhat effective". This new approach, he explained, targets the tumour and substances secreted by the tumour. "For the tumour to survive or the tumour cells that have spread, they need to develop a blood supply to provide nutrition. This new compound prohibits development of those blood vessels in theory proving very effective mechanisms for preventing development and spread of cancer."