A large retrospective case-control study revealed that women with a Melanoma diagnosis prior to age 30 presented with an almost 100% history of indoor suntanning facility use.
Amongst the 63 youngest women who presented with Melanoma diagnoses, 61 had a history of indoor tanning. Younger women reported earlier and more frequent use of indoor tanning facilities as compared with patients whose Melanoma diagnoses occurred later in life. A history of indoor tanning increased the likelihood of a Melanoma diagnosis by two to six times among women 30 to 49. Men were about 50% less likely than women to participate in indoor tanning, and data related to the association with Melanoma risk proved inconclusive.
The findings added to evidence linking indoor tanning to recent increases in Melanoma frequency among young women. The study also offered support for legislative and regulatory efforts to restrict access to and use of indoor tanning facilities, wrote DeAnn Lazovich, PhD, of the University of Minnesota in Minneapolis, and colleagues in JAMA Dermatology.
“Our results indicate that these efforts need to be accelerated and expanded beyond bans on minor access to indoor tanning to curb the Melanoma epidemic, which seems likely to continue unabated, especially among young women, unless exposure to indoor tanning is further restricted and reduced,” the authors stated, alluding to the FDA’s proposed ban on use of indoor tanning equipment by people younger than 18.
The study presents the strongest evidence to date regarding the association between indoor tanning and Melanoma, said Skin Cancer Specialist Mary Maloney, MD, of the University of Massachusetts Medical Center in Worcester.
“This study definitively links suntanning in salons with the development of Melanoma,” Maloney told MedPage Today. “I just don’t think you can argue with the epidemiologic results here, showing that women with more sessions of tanning and earlier tanning have a significant increase in Melanoma over those people who didn’t engage in that behavior or started later.”
The authors of an accompanying editorial praised Lazovich’s group for providing “important additional support for this hypothesis” that indoor tanning is the cause of the increased Melanoma occurrence in young women; however, the editorialists argued that the FDA proposal focusing on age restrictions doesn’t go far enough, citing loopholes in other attempts to restrict minors’ access to tanning facilities.
The focus on age also overlooks a simple fact: “most indoor tanners are adults, with about 85% estimated to be 18 years or older and therefore unaffected by age restrictions among minors,” Gery Guy Jr., PhD, of the Centers for Disease Control and Prevention in Atlanta, and colleagues wrote. Possible means of deterring indoor tanning include school policies, restrictions on sales of tanning equipment to the public, and counter-advertising to address “deceptive advertising by the indoor tanning industry.”
Until recently, a well-recognized increase in Melanoma incidence in the U.S. included higher rates in women until approximately age 50, followed by increases in both sexes. About 20 years ago, a sex-related divergence emerged, as a female predominance became apparent. Over the past decade, Melanoma occurrence not only has remainder higher in women but has increased at a more rapid rate in younger women compared with men.
The latest epidemiologic trends have been associated with anatomical changes in Melanoma lesion location, as truncal predominance among women has shifted to localization to other sites, whereas localization on the head and extremities among women has shifted toward more truncal lesions in younger women but not older women, the authors noted. The change in disease localization relates, in part, to increased use of indoor tanning equipment.
Lazovich and colleagues previously reported a drastic increase in Melanoma risk amongst users of indoor tanning equipment as compared with people who did not use tanning facilities. The study also exhibited a strong dose-response relationship, as Melanoma risk increased with frequency of indoor tanning.
To update and inform previous observations, the authors analyzed data from the Skin Health Study to explore the relationship between Melanoma to use of indoor tanning, age at initiation of indoor tanning, and frequency of indoor tanning. They performed separate analyses for men and women.
The analysis featured 681 patients with Melanoma diagnoses in Minnesota during 2004 and 2007. Women accounted for 68.2% (465) of the total patient population. The patients were matched by age and sex with a control group of 654 Melanoma-free individuals.
The authors concluded that women younger than 40 began indoor tanning at a younger age compared with women 40 to 49 (16 versus 25, P<0.001) and reported a significantly higher median number of tanning sessions (100 versus 40, P<0.001). Women younger than 30 had a 6-fold greater possibility of being among the Melanoma cases than in the control group (OR 6.0, 95% CI 1.3-28.5). Women 30 to 39 were 3.5 times more likely to be cases than controls, and 40 to 49 were 2.3 times more likely. A dose-response relationship between frequency of indoor tanning and Melanoma risk was seen across all age groups of women.
The data on men were not as revealing, as the relationship between indoor tanning and Melanoma was inconsistent. In the cases and control group combined, substantially fewer men reported indoor tanning (44.3% versus 78.2%), which could explain much of the inconsistency, the authors noted.
Study limitations included a small sample size and wide confidence intervals, the authors stated. Additionally, the case-control study design and low response rates could elicit concerns about selection and recall bias.