Pill could kill cancer

A pill that boosts the body's natural defences could help fight off all cancers and stop them ever returning, scientists believe. ''Delta-inhibitors'' were already known to help leukaemia patients, but researchers were amazed to find they also work on a whole range of other cancers.

The drugs, taken orally as a pill, were so successful in leukaemia trials that the control group, who were taking placebos, were immediately switched to the medication on ethical grounds.

Now scientists at UCL and the Babraham Institute in Cambridge have discovered that the same "delta inhibitors" are also effective against lung, pancreatic, skin and breast cancers, and probably many more.

Cancer suppresses the immune system by producing an enzyme called p100delta that tells it to power down, making it difficult for the body to fight the disease. The drugs "inhibit" that enzyme, allowing the immune system to attack tumour cells.

The added benefit is that, once the body has learned to fight off the cancer, it has inbuilt immunity, so the disease can never return, unlike if it had been killed by chemotherapy.

Although the study was conducted in mice, researchers are confident it would work in humans and are hopeful that human trials will begin soon.

"This helps your own immune system fight off the cancer better. The good guys win. And it seems to work on all cancers," said study co-leader Professor Bart Vanhaesebroeck of the UCL Cancer Institute, who first discovered the p110delta enzyme in 1997.

Tests found that inhibiting the enzyme in mice significantly increased cancer survival rates across a broad range of tumour types, both solid and blood cancers.

Mice given the drug survived breast cancer for almost twice as long. Their cancers also spread significantly less, with far fewer and smaller tumours developing. Survival after surgical removal of primary breast cancer tumours was also vastly improved.