Indoor tanning beds significantly increase the risk of developing melanoma, the deadliest form of skin cancer, the scientists from the United States reported last week.
According to the new findings, people who use tanning beds on a regular basis are 74 per cent more likely to develop melanoma when compared to individuals who do not visit tanning salons at all. And those who have tanning experience of ten years or more are the most at risk. "I think it is about time we began to focus on indoor tanning as a risk factor," said DeAnn Lazovich, epidemiologist from the University of Minnesota and a principal author of the new study.
For the purposes of their research, Lazovich and team studied 1,167 individuals who had been diagnosed with melanoma and compared them with 1,101 other individuals who did not have skin cancer. The average age of the participants was between 25 and 59 years old. All of them were asked to fill out a self-administered questionnaire, and after that were interviewed for one hour over the phone. The information gathered included such things as the age when a person started using tanning salons, its intensity in terms of duration and time of use, as well as exposure to sun rays and a variety of risk factors for melanoma.
The participants were also asked which type of tanning bed they had used - those that emit UVA rays or UVB rays. Based on the information collected the investigators were able to find out that the risk of developing melanoma was nearly 3 times greater among those who had been using tanning beds that emit UVB radiation and almost 4.5 times more for the devices that emitted UVA rays. Four different types of machines were investigated - conventional, high-pressure, high-speed and intensity, and sun lamps. The results revealed that individuals with melanoma were significantly more likely to have used any type of machine when compared to people in control group.
It was also established that individuals who had used an indoor tanning bed for between 1 and 9 hours in total were at an increased risk of developing skin cancer, but less likely to develop melanoma when compared to people who used tanning beds for more than 50 hours (more than 100 sessions) in total. Researchers said that the risk increased with use.
It is not a secret that ultraviolet radiation, whether from the sun or from tanning lamps, increases the risk of developing melanoma and other skin cancers. However, in the 80s, sunburn-causing UVB rays were believed to be the ones that are the most harmful, while deep-penetrating UVA rays were believed to be benign. And now this new study, the first to distinguish the difference between the exposure to UVA and UVB radiation, determined that tanning beds that emitted mostly UVA rays quadrupled the risk of developing melanoma for this group.
Statistically, each year melanoma affects approximately 69,000 Americans, and takes lives of about 9,000 people. The first signs of this deadly form of cancer include changes in shape or size of already existing mole, or the appearance of a new and unusual-looking growth on the skin. Other warning signs include itchiness, scaliness, change in texture, spreading of pigment into surrounding skin, or any bleeding.
The new findings are published in Cancer, Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.