Tape could simplify skin cancer diagnosis

The bad news about malignant melanoma is that the disease is increasing more rapidly than most other types of cancer. The good news is that it is easy to cure, as long as it is detected in time. A research group in Lund has therefore started a project that it is hoped will make it easier to correctly diagnose suspicious moles.

Kari Nielsen

Kari Nielsen (at the left). Photo: Roger Lundholm

The purpose of the project is to classify the moles using a molecular biology analysis that shows what genes are active in the tissue.

“It produces colour images with different patterns, in which it is easy to see a difference between benign tumours and tumours with a high risk of recurrence and metastasis. Our analysis of the images often agrees with what the dermatologists have found in their examination, but we also get extra information that can help make a more accurate diagnosis”, says cancer researcher Göran Jönsson.

The studies are to be based on samples taken from moles removed at the hospitals in Helsingborg, Lund and Malmö. This includes both obvious melanomas and moles with a suspicious appearance that are removed as a precaution. In the future, the latter type of operation may be avoidable.

“We will investigate whether it is possible to gather enough cells and RNA with a simple tape that is stuck to the mole and then pulled off”, says Kari Nielsen. She is a dermatologist at Helsingborg Hospital and part of the Lund Melanoma Study Group (see below).

If it is possible to obtain sufficient genetic material for an analysis using only tape, far fewer operations would have to be carried out. It would no longer be necessary to remove all suspicious moles as a precaution; instead, the tape samples could be analysed and only those that are really dangerous be removed. As surgery always leaves scars, which are sometimes unattractive or painful, this would be a major gain for patients.

Sun safety has been advocated for many years. Yet there are still serious gaps in the public’s knowledge, according to Kari Nielsen. Many believe that red skin is a preliminary stage towards the desired tan, but it isn’t at all. The redness is instead a sign of sunburn. As regards sun protection, a hat and covering up should be the first choice rather than sun cream.

The ability of sun cream to prevent malignant melanoma at all has been questioned until recently, when a study from Australia suggested a difference between those who had used or not used sun cream. The fact that this has not been demonstrated previously could be partly because older creams didn’t protect against all types of UV radiation and partly because many people did not use the creams correctly. You need to use more than just a thin layer of cream to achieve the desired sun protection.

“If you want to use sun cream as an additional measure to clothes, shade and a sun hat, you should also apply it several times a day, especially if you have been swimming or wiped your skin. However, sun cream can give a false sense of security. Because it stops you going red or burning, it is easy to believe that it’s all right to lie in the sun for as long as you like. But that’s not true”, warns Kari Nielsen.

Among other things, she has conducted research on nine Swedish families with a hereditary predisposition to melanoma. The people in those families who carried a risk gene often developed the disease early, between the age of 25 and 30.

“If you know that there is a lot of history of melanoma in your family, you should discuss this with a dermatologist. It may be appropriate to have regular check-ups”, says Kari Nielsen.

She also advises that all those who are worried about a mole that looks different, grows or bleeds should visit their doctor. It is better to go once too often than once too little, so that any melanomas are diagnosed as early as possible.

Ingela Björck

 Research grant

Lund Melanoma Study Group is a network of surgeons, dermatologists, research nurses and basic researchers focusing on malignant melanoma. The group is led by surgeon Christian Ingvar and cancer researchers Håkan Olsson and Göran Jönsson. The network received a grant of SEK 4 million earlier this year from the Mats Paulsson Foundation and the Stefan Paulsson Cancer Fund for research to improve knowledge of the disease.

Melanoma

• Skin cancer is increasing faster than any other type of cancer. Malignant melanoma is today the fifth most common cancer in women and the sixth most common in men.

• Approximately 3 300 new cases of malignant melanoma occur every year and over 500 patients die when the cancer spreads to other organs. If the disease is diagnosed early, however, it is very easy to cure.

• Most cases of melanoma are believed to be a result of burns from sunbathing and solarium use. Other risk factors are having pale skin and a large number of moles.

• Heredity plays a role in certain cases: between five and ten per cent of all cases of malignant melanoma are considered to have a hereditary background.