Researchers Urge Surgeon General to Announce UV Tanning Causes Skin Cancer

Study finds that UV tanning meets the same criteria as smoking as a cause of cancer.

The US Surgeon General should formally announce that UV tanning causes cancer based on the same criteria that smoking causes cancer, according to a recent study.

In 2014, acting Surgeon General Dr. Boris Lushniak released a call to action stating indoor tanning is strongly associated with an increased risk for skin cancer, but he did not say that tanning directly causes cancer. In a study published recently in the American Journal of Preventive Medicine, researchers argue an announcement that UV tanning directly causes cancer could save lives.

"In 1964 when the Surgeon General finally reported that smoking causes lung cancer, awareness and policy followed,” study senior author Robert P. Dellavalle, MD, PhD, MSPH, said in a press release. “Smoking rates declined and lung cancer rates have too. It's time for the Surgeon General to say the same thing about UV tanning.”

Based on 9 criteria that determine a causal relationship in disease and cause that was also used in the context of smoking and lung cancer in 1965, the researchers note that smoking and UV tanning both meet 8 of the 9 criteria:

1. Strength of Association

Large population analyses found that the risk of skin cancer is approximately 16% more likely in people who reported ever using a tanning bed. Meanwhile, smokers are 35% more likely than non-smokers to develop lung cancer. In terms of epidemiology, however, the 16% increased skin cancer risk for tanning bed users remains strong, the study noted.

2. Consistency of Association

Researchers found the association between UV tanning and skin cancer is not limited to a specific population or nationality, but is instead consistent across all studies.

3. Specificity

The researchers note that the cause leading to numerous effects is more difficult to pinpoint than a cause leading to one effect, but the one-to-one relationship between UV radiation and skin cancer has long been established.

4. Temporality

In the case of UV tanning and skin cancer, the study notes that the ever-use of tanning beds precedes the increased risk for skin cancer.

5. Biological Gradient

The more people use UV tanning beds, the more likely they will get skin cancer. The researchers note that for every additional tanning bed session per year, there is a 1.8% increase in the risk of melanoma.

6. Plausibility

In determining whether there is a plausible way UV tanning can cause skin cancer, the study notes that UV rays from tanning beds penetrate the epidermal layer of the skin, which may cause DNA alternations that promote cancer formation.

7. Coherence

Coherent data exists between lab experiments and population studies, which both point to a similar conclusion.

8. Experiment

Animal models have previously shown UV radiation to cause skin cancer. However, short of a randomized control trial to test the effect of UV tanning on cancer, the tanning industry can continue to claim a lack of true science behind the cancer-causing effects of UV tanning, according to the study.

9. Analogy

The researchers note that people with skin types susceptible to sunburns have higher rates of skin cancer, which is analogous to tanning as the more burned a person gets, the higher risk of skin cancer they face.

While most cancers are considered to be the result of random genetic mutations that allow cells to act cancerous, the researchers note the importance of behavioral changes to lower the risk of preventable cancers.

"Skin cancer and lung cancer are preventable types of cancer - reduce smoking and you reduce lung cancer; reduce UV exposure and you reduce skin cancer. It's much easier to help people understand that indoor tanning causes cancer than it is to message something more convoluted about 'association'," Dr. Dellavalle said. "Tanning beds cause skin cancer. It is time to now more openly announce this causality."