Experts Crunch the Numbers on Indoor Tanning

Just Four Annual Visits Multiplies Skin Cancer Risks

New research indicates that people who tan indoors four times a year increase their risk of developing the non-melanoma skin cancers basal and squamous cell carcinoma by 15 percent, and their risk of melanoma by 11 percent. Non-melanoma skin cancer can be disfiguring and sometimes life-threatening, and melanoma, the deadliest form of skin cancer, will kill an estimated 8,790 people in the US this year alone. While it has been known for some time that indoor ultraviolet (UV) radiation tanning heightens the risk of developing all forms of skin cancer, with this study, researchers have more precisely quantified the risks.

Investigators led by Mingfeng Zhang, MD, research fellow at Brigham and Women’s Hospital and Harvard Medical School in Boston, examined data about tanning bed use collected from more than 73,000 female nurses in the Nurses’ Health Study II between 1989 and 2009. The researchers looked at indoor tanning among subjects during both high school and college, and then from ages 25 to 35. In addition to demonstrating a dose-response effect (that is, the more extensive their indoor tanning, the higher their risk of developing skin cancer), the numbers suggest that younger tanners are especially at risk: “Tanning bed use during high school and college conferred a higher risk of basal cell carcinoma (BCC) than did tanning bed use between ages 25 and 35,” Dr. Zhang said. In fact, just one indoor tanning session a year while the subjects were in high school or college boosted their risk of developing BCC by 10 percent, and those who tanned indoors more than six times a year had an 82 percent higher risk of developing BCC than non-tanners.

The final version of the research paper is not yet available, but the authors presented their findings at a recent meeting of the Association for Cancer Research (AACR). “We provided further evidence of the increased risk caused by tanning beds for all three types of skin cancers,” Dr. Zhang said. “This finding should be a warning to the public about the dangers of tanning beds.”