(HealthDay News) — Indoor tanning, even without burns, increases the risk of melanoma, according to a study published online May 28 in the Journal of the National Cancer Institute.
Rachel Isaksson Vogel, of the University of Minnesota in Minneapolis, and colleagues used data from a case-control study involving 1,167 patients who had been diagnosed with invasive cutaneous melanoma between 2004 and 2007 and 1,101 control subjects who were matched by age and sex.
The researchers sought to assess the risk of melanoma associated with indoor tanning. The researchers adjusted for eye, hair, and skin color; number of freckles and moles; family history of melanoma; and lifetime sun exposure and sunscreen use.
The researchers found that, overall, 56.8% of all patients reported five or more lifetime sunburns, and 5.3% reported never having been sunburned.
Patients with melanoma reporting zero lifetime sunburns were nearly four times more likely to be indoor tanners compared with control subjects (odds ratio, 3.87; P = 0.002). Patients with melanoma also tended to initiate indoor tanning at a younger age and reported the highest number of years and sessions of indoor tanning, compared with other patients who had experienced sunburn.
“Tanning indoors without burning may allow for greater cumulative exposure to the damaging effects of artificial and/or solar UV [ultraviolet] radiation,” the researchers wrote. “The intensity and proportion of UV-A and UV-B emitted by tanning devices have been shown to differ from the sun in ways that could increase risks associated with indoor tanning.”