Scientists have found a way to predict whether skin cancers will spread to other organs.
Melanoma is a dangerous form of skin cancer
It works by measuring the density of the lymph vessels around malignant melanomas.
The researchers from Bristol University and Frenchay Hospital hope their work will help doctors target resources on those most at need of close follow-up.
The research is published in the British Journal of Cancer. UK cases of skin cancer are increasing sharply.
Between 1995 and 2000 the number of people diagnosed with melanoma increased by 24% - to almost 7,000 cases.
And around 1,600 people die from the disease every year when the melanoma spreads to other parts of the body.
Previously, doctors have predicted whether skin cancer was likely to spread by measuring its thickness.
Doctors believed that the thicker a tumour was, the more likely it was to spread.
However, many thinner melanomas also spread and only 40% of the thicker kind
The Bristol team examined melanoma samples stored at the Frenchay.
They measured the density of lymph vessels around the melanomas, and then assessed which patients actually went on to develop secondary cancers within eight years.
Dr David Bates, scientific director of the Microvascular Research Laboratories
at Bristol University, said: "We shall now be looking at a larger study of many
hundreds of patients.
"If our findings are confirmed it will mean that the likelihood of a patient developing cancer in other organs could be predicted ahead of time with reasonable certainty.
"Resources can then be concentrated on those patients most in need of close
follow up, and hopefully lead to earlier detection of the spread of cancer."