No wonder-drug likely for cancer, says Nobel scientist

Smarter drugs for fighting cancer will begin to emerge as more is understood about cancer cells - but don't expect a wonder drug that cures all forms of cancer, says a leading international researcher.

Nobel Laureate Sir Tim Hunt, principal scientist at Cancer Research UK and keynote speaker at the Queenstown Molecular Biology Meeting, said an improved understanding of the way cancer cells divided and grew had already yielded smart drugs such as Glivec and Herceptin.

But he says the discovery of the cancer-fighting equivalent of penicillin is unlikely.

"Once you have that kind of example of a magic wonder drug, [people think] 'well, gosh there must be wonder drugs for every kind of human disease'. It's raised the bar awfully high," he said.

"Basically cancer cells grow using all the same mechanisms that normal cells in the body use. So you could stop the cancer cell growing by standing the right distance from an atom bomb, but then all your other cells also stop growing at the same time."

A well-designed drug compound would need to target only cancerous cells, while leaving normal cells unharmed.

But the understanding thus far of cancerous cells had not yielded the clinical results promised in the laboratory, although two, Glivec and Herceptin, were cited as examples of a promising new generation of cancer drugs.

Sir Tim said Glivec was initially tested on very rare tumours, but by "good luck" was found to be effective in some more common cancers, such as chronic myeloid leukaemia, which was previously untreatable.