Malignant melanoma has become increasingly common in the Western world over the past few decades. One of the biggest factors has been excessive and unprotected sunbathing despite widespread awareness of the health risks.
Long time to develop
Melanoma takes a long time, sometimes several decades, to develop. For that reason, sunbathing habits from many years ago still affect a person’s risk level.
According to a new study by researchers at Sahlgrenska Academy, University of Gothenburg, the number of melanoma cases in the Västra Götaland region has quadrupled among men and tripled among women since 1970.
Increase above average
“This represents a relative increase of more than 3% per year,” says Magdalena Claeson, a researcher at Sahlgrenska Academy who participated in the study. “The increase in the region was considerably above average for the entire country.”
The study found that 35% more men and 25% more women developed malignant melanoma in Gothenburg than in the inland municipalities. Fifteen per cent more women developed the disease in the coastal municipalities than inland.
More exposure to the sun
One explanation is that inhabitants of Gothenburg and the coastal municipalities are exposed to the sun for more hours a day. A 2007 study conducted by the Swedish National Board of Health and Welfare found that inhabitants of Gothenburg and the coastal municipalities tend to take longer summer holidays in sunny countries and spend more time outdoors when abroad. Meanwhile, they are more likely to work indoors when they are in Sweden.
“The latest research suggests that melanoma is caused by this type of intermittent exposure to the sun,” Claeson says. “In other words, people get sunburned during their summer holiday and spend a lot of time indoors for the rest of the year.”
Preventive resource needed
The results have convinced the researchers that more preventive resources should be appropriated for the Västra Götaland region, particularly Gothenburg and the coastal municipalities.
“Among the measures likely to prove effective are educational initiatives among schoolchildren and sun protection information for people who travel abroad,” Claeson says.
The article, entitled “Incidence of Cutaneous Melanoma in Western Sweden, 1970-2007,” has been accepted for publication in Melanoma Research.
Magdalena Claeson, doctoral student at the Department of Dermatology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University
Phone +46 31-243445, +46 735-515732
Approximately 2,800 Swedes develop, and 470 die of, malignant melanoma every year. More common in southern than northern Sweden, the disease is the sixth most common — and the fastest growing — type of cancer in the country. Though melanoma can develop at any age, it is extremely rare in children. Avoiding excessive total exposure to the sun throughout life, as well as not getting sunburned, is the best way of reducing the risk for malignant melanoma and other kinds of skin cancer. The rule of thumb is that the earlier melanoma is detected, the greater the chances of recovery.
FACTS: HOW TO SUNBATHE SAFELY
• Stay out of the sun between 11 am and 3 pm
• Wear a wide-brimmed hat, long-sleeve shirt, trousers, etc.
• Use sunscreen (sun protection factor 30-50) as a supplement
• Do not use solariums
• See a doctor if you notice a birthmark that changes colour, shape or size
Image below: The middle of the image shows a preliminary stage of malignant melanoma.
Photo: Sahlgrenska Academy