Vital tumour genes pinpointed

A genetic signature contols skin cancer tumour development

Scientists have discovered a possible way to identify which patients who develop a potentially deadly form of skin cancer are most at risk of the disease spreading.

They have uncovered tell-tale genetic differences between different types of malignant melanoma tumour.

The breakthrough could lead to better diagnosis and treatment of a disease which is becoming increasingly common.

The international study, led by the US National Human Genome Research Institute (NHGRI), involves scientists from 11 laboratories in the United States, Australia, and Israel.

This is a glimpse into the secret life of the melanoma cell

Dr Vernon Sondak, University of Michigan in Ann Arbor

It was made possible by the wealth of information generated by the international Human Genome Project.

Scientists have long known that melanoma is more aggressive in some patients than others.

But they have been unable to identify which patients are most at risk.

The new study employed a technique called gene expression profiling to analyse the genetic make-up of cancer tumours.

The technology enabled scientists to isolate a particular set of genetic differences present in less aggressive forms of the cancer.

The scientists studied 40 patients with malignant melanoma.

They found that 19 patients with a less aggressive form of the disease had a very similar genetic pattern which was different to that found in patients with more aggressive tumours.

Real breakthrough

Researcher Professor Bert Vogelstein, of Johns Hopkins University, said: "This paper represents a remarkable example of the power of gene expression profiling.

The results provide information that should be useful for the management of patients with melanoma

Professor Bert Vogelstein

"The results not only offer intriguing insights into the biology, but also provide information that should be useful for the management of patients with melanoma."

Co-researcher Dr Vernon Sondak, associate professor of surgery at the University of Michigan in Ann Arbor, said the results would change the way scientists think about melanoma and how doctors will treat it in the future.

"This is a glimpse into the secret life of the melanoma cell.

"If melanoma is caught in its early stages, it's extremely treatable.

"But in its later stages, it can be unpredictably aggressive or not aggressive. We now have a new tool for figuring out how the tumour got to be that way."

Malignancies of the skin are the most common human cancers, and melanoma is the most serious form of skin cancer.

In many parts of the world, melanoma rates are rising faster than those of any other cancer.

Experts believe that much of this increase is due to people's greater exposure to the sun's ultraviolet radiation, which can cause misspellings in DNA and, as a result, damage skin cells.

The research is published in the journal Nature.