A community of dwarfs living in a remote corner of Ecuador could hold the key to curing cancer, according to scientists.

The Laron dwarfs, who are in perfect proportion but grow only to an average height of 4ft, appear to be immune to all forms of the disease and are long-lived.

Now scientists studying a hormone present in other humans but which is lacking in the dwarfs believe their findings could lead to the development of an effective anti-cancer drug.

Leading British cancer experts have welcomed the research, which they said could be important in preventing the killer disease.

New hope: The Laron dwarfs from Ecuador who are immune to cancer

There are a little more than 300 people in the world with the condition Laron dwarfism, a third of whom live in remote villages in Ecuador’s southern Loja province.

Sufferers of Laron – believed to be caused by inbreeding – lack a hormone called Insulin-like Growth Factor 1, or IGF1.

Research uncovered during an investigation by Channel 4’s More4 News suggests this is the reason for their longevity and apparent immunity to cancer. In ordinary humans, too much of the hormone can lead a person to develop breast, prostate or bowel cancers at an early age.

Dr Jaime Guevara-Aguirre, a hormone expert from the Ecuadorian Institute of Endocrinology, who has been studying Laron dwarfism for more than ten years, said: ‘We’ve discovered that people with Laron simply don’t get cancer.

‘Cancer can be detected in their relatives of a normal size, but never in my patients – not one single case.

‘Every experiment has demonstrated that high levels of IGF1 are associated with cancer, but these patients have low levels of IGF1 and an absence of the disease.’

According to Dr Guevara-Aguirre, finding a way to reduce levels of IGF1 could mean finding a way to prevent cancer from developing. ‘Medically, this is very, very exciting,’ he said.

The Laron dwarfs could also have implications for the prevention of diabetes, he said. Despite a tendency to obesity due to overeating and a poor diet, it is another condition to which they appear immune.

Research has also been carried out by Dr Valter Longo at the University of Southern California. When he reproduced the Laron mutation in mice, he found that they lived ten times longer than normal mice.

He believes that having less IGF1 could mean suffering less of the DNA damage that occurs in all of us when we age and which leads to cancer.

Cancer cells: Scientists hoping to develop a new drug will examine the dwarfs' hormones

Dr Longo said: ‘In the mice, we have identified pathways – sets of genes connected to each other – that extend their lifespan. However, the pathways not only affect longevity but also the DNA damage that accumulates with ageing and plays a central role in cancer.

‘We are working on proving a definite link between the genetic mutations and a much reduced cancer rate. If we can do that it would provide a human gene target for a potentially highly effective cancer-prevention drug.’

Professor Bass Hassan, a medical oncologist with Cancer Research UK and a scientist at Oxford University, said the research could have important consequences.

‘Research has shown that mistakes in certain genes can prevent cancer,’ he said.

‘Laboratory work in mice, flies and worms has shown that if IGF1 is removed, the animals tend not to get cancer and to live longer. This is now mirrored in recent research into small humans, who turn out to have little or no IGF1, as is the case with Laron dwarfs.

‘Recent work suggests it might be possible to reduce IGF1 and so live longer with a reduced risk of cancer.’

Professor Hassan added: ‘This might lead us into a very important aspect of cancer prevention in the future but it is an area that still needs more research.’